Tagged: NSLS-II Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 11:35 am on July 12, 2019 Permalink | Reply
    Tags: "Optimizing the Growth of Coatings on Nanowire Catalysts", , , , NSLS-II,   

    From Brookhaven National Lab: “Optimizing the Growth of Coatings on Nanowire Catalysts” 

    From Brookhaven National Lab

    July 8, 2019
    Ariana Manglaviti
    amanglaviti@bnl.gov
    (631) 344-2347

    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    1
    (Sitting from front) Iradwikanari Waluyo, Mingzhao Liu, Dario Stacchiola, (standing from front) Mehmet Topsakal, Mark Hybertsen, Deyu Lu, and Eli Stavitski at the Inner-Shell Spectroscopy beamline of Brookhaven Lab’s National Synchrotron Light Source II (NSLS-II). The scientists performed x-ray absorption spectroscopy experiments at NSLS-II to characterize the chemical state of titanium dioxide (titania) coatings on zinc oxide nanowires. They chemically processed the nanowires to make the coatings—which boost the efficiency of the nanowires in catalyzing the water-splitting reaction that produces oxygen and hydrogen, a sustainable fuel—more likely to adhere. These characterization results were coupled with electron microscopy imaging and theoretical analyses to generate a model of the amorphous (noncrystal) atomic structure of titania.

    Scientists chemically treated the surface of wire-looking nanostructures made of zinc oxide to apply a uniform coating of titanium dioxide; these semiconducting nanowires could be used as high-activity catalysts for solar fuel production.

    Solar energy harvested by semiconductors—materials whose electrical resistance is in between that of regular metals and insulators—can trigger surface electrochemical reactions to generate clean and sustainable fuels such as hydrogen. Highly stable and active catalysts are needed to accelerate these reactions, especially to split water molecules into oxygen and hydrogen. Scientists have identified several strong light-absorbing semiconductors as potential catalysts; however, because of photocorrosion, many of these catalysts lose their activity for the water-splitting reaction. Light-induced corrosion, or photocorrosion, occurs when the catalyst itself undergoes chemical reactions (oxidation or reduction) via charge carriers (electrons and “holes,” or missing electrons) generated by light excitation. This degradation limits catalytic activity.

    Now, scientists from the Center for Functional Nanomaterials (CFN)—a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven National Laboratory—have come up with a technique for optimizing the activity of one such catalyst: 500-nanometer-long but relatively thin (40 to 50 nanometers) wire-looking nanostructures, or nanowires, made of zinc oxide (ZnO). Their technique—described in a paper published online in Nano Letters on May 3—involves chemically treating the surface of the nanowires in such a way that they can be uniformly coated with an ultrathin (two to three nanometers thick) film of titanium dioxide (titania), which acts as both a catalyst and protective layer.

    The CFN-led research is a collaboration between Brookhaven Lab’s National Synchrotron Light Source II (NSLS-II)—another DOE Office of Science User Facility— and Computational Science Initiative (CSI); the Center for Computational Materials Science at the Naval Research Laboratory; and the Department of Materials Science and Chemical Engineering at Stony Brook University.

    “Nanowires are ideal catalyst structures because they have a large surface area for absorbing light, and ZnO is an earth-abundant material that strongly absorbs ultraviolet light and has high electron mobility,” said co-corresponding author and study lead Mingzhao Liu, a scientist in the CFN Interface Science and Catalysis Group. “However, by themselves, ZnO nanowires do not have high enough catalytic activity or stability for the water-splitting reaction. Uniformly coating them with ultrathin films of titania, another low-cost material that is chemically more stable and more active in promoting interfacial charge transfer, enhances these properties to boost reaction efficiency by 20 percent compared to pure ZnO nanowires.”

    3
    (Background) A false-colored scanning electron microscope image of zinc oxide (ZnO) nanowires coated with titanium dioxide, or titania (TiO2). On average, the nanowires are 10 times longer than they are wide. The white-dashed inset contains a high-resolution transmission electron microscope image that distinguishes between the ZnO core and titania shell. The black-dashed inset features a structural model of the amorphous titania shell, with the red circles corresponding to oxygen atoms and the green and blue polyhedra corresponding to undercoordinated and coordinated titanium atoms, respectively.

    To “wet” the surface of the nanowires for the titania coating, the scientists combined two surface processing methods: thermal annealing and low-pressure plasma sputtering. For the thermal annealing, they heated the nanowires in an oxygen environment to remove defects and contaminants; for the plasma sputtering, they bombarded the nanowires with energetic oxygen gas ions (plasma), which ejected oxygen atoms from the ZnO surface.

    “These treatments modify the surface chemistry of the nanowires in such a way that the titania coating is more likely to adhere during atomic layer deposition,” explained Liu. “In atomic layer deposition, different chemical precursors react with a material surface in a sequential manner to build thin films with one layer of atoms at a time.”

    The scientists imaged the nanowire-shell structures with transmission electron microscopes at the CFN, shining a beam of electrons through the sample and detecting the transmitted electrons. However, because the ultrathin titania layer is not crystalline, they needed to use other methods to decipher its “amorphous” structure. They performed x-ray absorption spectroscopy experiments at two NSLS-II beamlines: Inner-Shell Spectroscopy (ISS) and In situ and Operando Soft X-ray Spectroscopy (IOS).

    “The x-ray energies at the two beamlines are different, so the x-rays interact with different electronic levels in the titanium atoms,” said co-author Eli Stavitski, ISS beamline physicist. “The complementary absorption spectra generated through these experiments confirmed the highly amorphous structure of titania, with crystalline domains limited to a few nanometers. The results also gave us information about the valence (charge) state of the titanium atoms—how many electrons are in the outermost shell surrounding the nucleus—and the coordination sphere, or the number of nearest neighboring oxygen atoms.”

    Theorists and computational scientists on the team then determined the most likely atomic structure associated with these experimental spectra. In materials with crystalline structure, the arrangement of an atom and its neighbors is the same throughout the crystal. But amorphous structures lack this uniformity or long-range order.

    “We had to figure out the correct combination of structural configurations responsible for the amorphous nature of the material,” explained co-corresponding author Deyu Lu, a scientist in the CFN Theory and Computation Group. “First, we screened an existing structural database and identified more than 300 relevant local structures using data analytics tools previously developed by former CFN postdoc Mehmet Topsakal and CSI computational scientist Shinjae Yoo. We calculated the x-ray absorption spectra for each of these structures and selected 11 representative ones as basis functions to fit our experimental results. From this analysis, we determined the percentage of titanium atoms with a particular local coordination.”

    The analysis showed that about half of the titanium atoms were “undercoordinated.” In other words, these titanium atoms were surrounded by only four or five oxygen atoms, unlike the structures in most common forms of titania, which have six neighboring oxygen atoms.

    To validate the theoretical result, Lu and the other theorists—Mark Hybertsen, leader of the CFN Theory and Computation Group; CFN postdoc Sencer Selcuk; and former CFN postdoc John Lyons, now a physical scientist at the Naval Research Lab—created an atomic-scale model of the amorphous titania structure. They applied the computational technique of molecular dynamics to simulate the annealing process that produced the amorphous structure. With this model, they also computed the x-ray absorption spectrum of titania; their calculations confirmed that about 50 percent of the titanium atoms were undercoordinated.

    “These two independent methods gave us a consistent message about the local structure of titania,” said Lu.

    “Fully coordinated atoms are not very active because they cannot bind to the molecules they do chemistry with in reactions,” explained Stavitski. “To make catalysts more active, we need to reduce their coordination.”

    “Amorphous titania transport behavior is very different from bulk titania,” added Liu. “Amorphous titania can efficiently transport both holes and electrons as active charge carriers, which drive the water-splitting reaction. But to understand why, we need to know the key atomic-scale motifs.”

    To the best of their knowledge, the scientists are the first to study amorphous titania at such a fine scale.

    “To understand the structural evolution of titania on the atomic level, we needed scientists who know how to grow active materials, how to characterize these materials with the tools that exist at the CFN and NSLS-II, and how to make sense of the characterization results by leveraging theory tools,” said Stavitski.

    Next, the team will extend their approach of combining experimental and theoretical spectroscopy data analysis to materials relevant to quantum information science (QIS). The emerging field of QIS takes advantage of the quantum effects in physics, or the strange behaviors and interactions that happen at ultrasmall scales. They hope that CFN and NSLS-II users will make use of the approach in other research fields, such as energy storage.

    This research used resources of Brookhaven Lab’s Scientific Data and Computing Center (part of CSI) and the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility operated by Lawrence Berkeley National Laboratory. The computational studies were in part supported by a DOE Laboratory Directed Research and Development (LDRD) project and the Office of Naval Research through the Naval Research Laboratory’s Basic Research Program.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    BNL Campus


    BNL Center for Functional Nanomaterials

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 12:23 pm on July 5, 2019 Permalink | Reply
    Tags: "Creating 'Movies' of Thin Film Growth at NSLS-II", , Coherent x-rays at NSLS-II enable researchers to produce more accurate observations of thin film growth in real time., NSLS-II, The team used a technique called x-ray photon correlation spectroscopy., Thin films are used to build some of today’s most important technologies such as computer chips and solar cells.   

    From Brookhaven National Lab “Creating ‘Movies’ of Thin Film Growth at NSLS-II” 

    From Brookhaven National Lab

    July 2, 2019
    Stephanie Kossman
    skossman@bnl.gov

    Coherent x-rays at NSLS-II enable researchers to produce more accurate observations of thin film growth in real time.

    1
    Co-authors Peco Myint (BU) and Jeffrey Ulbrandt (UVM) are shown at NSLS-II’s CHX beamline, where the research was conducted.

    From paint on a wall to tinted car windows, thin films make up a wide variety of materials found in ordinary life. But thin films are also used to build some of today’s most important technologies, such as computer chips and solar cells. Seeking to improve the performance of these technologies, scientists are studying the mechanisms that drive molecules to uniformly stack together in layers—a process called crystalline thin film growth. Now, a new research technique could help scientists understand this growth process better than ever before.

    Researchers from the University of Vermont, Boston University, and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have demonstrated a new experimental capability for watching thin film growth in real-time. Using the National Synchrotron Light Source II (NSLS-II)—a DOE Office of Science User Facility at Brookhaven—the researchers were able to produce a “movie” of thin film growth that depicts the process more accurately than traditional techniques can. Their research was published on June 14, 2019 in Nature Communications.

    2
    This animation is a simplified representation of thin film growth. As C60 molecules are deposited onto a material, they form multiple layers simultaneously—not one layer at a time. After a molecule reaches the surface of the material, it migrates by surface diffusion towards the boundary of an existing layer, or the “step-edge,” causing the step-edge to move out from the center of the mound. This process repeats as new layers are continuously formed in an organized pattern. The mound increases in height by one layer after an equivalent of one full layer of molecules has been deposited onto the material. The pattern of step-edges is self-similar after each full-layer-equivalent is deposited, just displaced one layer higher. The main result of the study is that this repeating self-similarity, or “autocorrelation,” can be quantitatively measured with coherent x-rays, and that the autocorrelations can be used to deduce certain details of how step-edges propagate during the deposition.

    How thin films grow

    Like building a brick wall, thin films “grow” by stacking in overlapping layers. In this study, the scientists focused on the growth process of a nanomaterial called C60, which is popular for its use in organic solar cells.

    “C60 is a spherical molecule that has the structure of a soccer ball,” said University of Vermont physicist Randall Headrick, lead author of the research. “There is a carbon atom at all of the corners where the ‘black’ and ‘white’ patches meet, for a total of 60 carbon atoms.”

    Though spherical C60 molecules don’t perfectly fit side-by-side like bricks in wall, they still create a uniform pattern.

    “Imagine you have a big bin and you fill it with one layer of marbles,” Headrick said. “The marbles would pack together in a nice hexagonal pattern along the bottom of the bin. Then, when you laid down the next layer of marbles, they would fit into the hollow areas between the marbles in the bottom layer, forming another perfect layer. We’re studying the mechanism that causes the marbles, or molecules, to find these ordered sites.”

    But in real life, thin films don’t stack this evenly. When filling a bin with marbles, for example, you may have three layers of marbles on one side of the bin and only one layer on the other side. Traditionally, this nonuniformity in thin films has been difficult to measure.

    “In other experiments, we could only study a single crystal that was specially polished so the whole surface behaved the same way at the same time,” Headrick said. “But that is not how materials behave in real life.”

    Studying thin film growth through coherent x-rays

    4
    A snapshot of the speckle pattern “movie” produced at CHX. The speckles are most visible at the boundaries of each color.

    To collect data that more accurately described thin film growth, Headrick went to the Coherent Hard X-ray Scattering (CHX) beamline at NSLS-II to design a new kind of experiment, one that made use of the beamline’s coherent x-rays. The team used a technique called x-ray photon correlation spectroscopy.

    “Typically, when you do an x-ray experiment, you see average information, like the average size of molecules or the average distance between them. And as the surface of a material become less uniform or ‘rougher,’ the features you look for disappear,” said Andrei Fluerasu, lead beamline scientist at CHX and a co-author of the research. “What is special about CHX is that we can use a coherent x-ray beam that produces an interference pattern, which can be thought of like a fingerprint. As a material grows and changes, its fingerprint does as well.”

    The “fingerprint” produced by CHX appears as a speckle pattern and it represents the exact arrangement of molecules in the top layer of the material. As layers continue to stack, scientists can watch the fingerprint change as if it were a movie of the thin film growth.

    “That is impossible to measure with other techniques,” Fluerasu said.

    Through computer processing, the scientists are able to convert the speckle patterns into correlation functions that are easier to interpret.

    “There are instruments like high resolution microscopes that can actually make a real image of these kinds of materials, but these images usually only show narrow views of the material,” Headrick said. “A speckle pattern that changes over time is not as intuitive, but it provides us with data that is much more relevant to the real-life case.”

    Co-author Lutz Wiegart, a beamline scientist at CHX, added, “This technique allows us to understand the dynamics of growth processes and, therefore, figure out how they relate to the quality of the films and how we can tune the processes.”

    The detailed observations of C60 from this study could be used to improve the performance of organic solar cells. Moving forward, the researchers plan to use this technique to study other types of thin films as well.

    5
    Members of the collaborating institutions are shown at NSLS-II’s CHX beamline. Pictured from left to right are Karl F. Ludwig Jr. (BU), Lutz Wiegart (NSLS-II), Randall Headrick (UVM), Xiaozhi Zhang (UVM), Jeffrey Ulbrandt (UVM), Yugang Zhang (NSLS-II), Andrei Fluerasu (NSLS-II), and Peco Myint (BU).

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    BNL Campus


    BNL Center for Functional Nanomaterials

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 12:22 pm on May 10, 2019 Permalink | Reply
    Tags: , , , NSLS-II, , ,   

    From Brookhaven National Lab: “New Approach for Solving Protein Structures from Tiny Crystals” 

    From Brookhaven National Lab

    May 3, 2019
    Karen McNulty Walsh
    kmcnulty@bnl.gov
    (631) 344-8350

    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    Technique opens door for studies of countless hard-to-crystallize proteins involved in health and disease.

    1
    Wuxian Shi, Martin Fuchs, Sean McSweeney, Babak Andi, and Qun Liu at the FMX beamline at Brookhaven Lab’s National Synchrotron Light Source II [see below], which was used to determine a protein structure from thousands of tiny crystals.

    Using x-rays to reveal the atomic-scale 3-D structures of proteins has led to countless advances in understanding how these molecules work in bacteria, viruses, plants, and humans—and has guided the development of precision drugs to combat diseases such as cancer and AIDS. But many proteins can’t be grown into crystals large enough for their atomic arrangements to be deciphered. To tackle this challenge, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and colleagues at Columbia University have developed a new approach for solving protein structures from tiny crystals.

    The method relies on unique sample-handling, signal-extraction, and data-assembly approaches, and a beamline capable of focusing intense x-rays at Brookhaven’s National Synchrotron Light Source II (NSLS-II)—a DOE Office of Science user facility—to a millionth-of-a-meter spot, about one-fiftieth the width of a human hair.

    “Our technique really opens the door to dealing with microcrystals that have been previously inaccessible, including difficult-to-crystallize cell-surface receptors and other membrane proteins, flexible proteins, and many complex human proteins,” said Brookhaven Lab scientist Qun Liu, the corresponding author on the study, which was published on May 3 in IUCrJ, a journal of the International Union of Crystallography.

    Deciphering protein structures

    Protein crystallography has been a dominant method for solving protein structures since 1958, improving over time as x-ray sources have grown more powerful, allowing more precise structure determinations. To determine a protein structure, scientists measure how x-rays like those generated at NSLS-II diffract, or bounce off, the atoms in an ordered crystalline lattice consisting of many copies of the same protein molecule all arrayed the same way. The diffraction pattern conveys information about where the atoms are located. But it’s not sufficient.

    2
    A cartoon representing the structure of a well-studied plant protein that served as a test case for the newly developed microcrystallography technique. Magenta mesh patterns surrounding sulfur atoms intrinsic to the protein (yellow spheres) indicate the anomalous signals that were extracted using low-energy x-ray diffraction of thousands of crystals measuring less than 10 millionths of a meter, the size of a bacterium.

    “Only the amplitudes of diffracted x-ray ‘waves’ are recorded on the detector, but not their phases (the timing between waves),” said Liu. “Both are required to reconstruct a 3-D structure. This is the so-called crystallographic phase problem.”

    Crystallographers have solved this problem by collecting phase data from a different kind of scattering, known as anomalous scattering. Anomalous scattering occurs when atoms heavier than a protein’s main components of carbon, hydrogen, and nitrogen absorb and re-emit some of the x-rays. This happens when the x-ray energy is close to the energy those heavy atoms like to absorb. Scientists sometimes artificially insert heavy atoms such as selenium or platinum into the protein for this purpose. But sulfur atoms, which appear naturally throughout protein molecules, can also produce such signals, albeit weaker. Even though these anomalous signals are weak, a big crystal usually has enough copies of the protein with enough sulfur atoms to make them measurable. That gives scientists the phase information needed to pinpoint the location of the sulfur atoms and translate the diffraction patterns into a full 3-D structure.

    “Once you know the sulfur positions, you can calculate the phases for the other protein atoms because the relationship between the sulfur and the other atoms is fixed,” said Liu.

    But tiny crystals, by definition, don’t have that many copies of the protein of interest. So instead of looking for diffraction and phase information from repeat copies of a protein in a single large crystal, the Brookhaven/Columbia team developed a way to take measurements from many tiny crystals, and then assemble the collective data.

    Tiny crystals, big results

    To handle the tiny crystals, the team developed sample grids patterned with micro-sized wells. After pouring solvent containing the microcrystals over these well-mount grids, the scientists removed the solvent and froze the crystals that were trapped on the grids.

    3
    Micro-patterned sample grids for manipulation of microcrystals.

    “We still have a challenge, though, because we can’t see where the tiny crystals are on our grid,” said Liu. “To find out, we used microdiffraction at NSLS-II’s Frontier Microfocusing Macromolecular Crystallography (FMX) beamline to survey the whole grid. Scanning line by line, we can find where those crystals are hidden.”

    As Martin Fuchs, the lead beamline scientist at FMX, explained, “The FMX beamline can focus the full intensity of the x-ray beam down to a size of one micron, or millionth of a meter. We can finely control the beam size to match it to the size of the crystals—five microns in the case of the current experiment. These capabilities are crucial to obtain the best signal,” he said.

    Wuxian Shi, another FMX beamline scientist, noted that “the data collected in the grid survey contains information about the crystals’ location. In addition, we can also see how well each crystal diffracts, which allows us to pick only the best crystals for data collection.”

    The scientists were then able to maneuver the sample holder to place each mapped out microcrystal of interest back in the center of the precision x-ray beam for data collection.

    They used the lowest energy available at the beamline—tuned to approach as closely as possible sulfur atoms’ absorption energy—and collected anomalous scattering data.

    “Most crystallographic beamlines could not reach the sulfur absorption edge for optimized anomalous signals,” said co-author Wayne Hendrickson of Columbia University. “Fortunately, NSLS-II is a world-leading synchrotron light source providing bright x-rays covering a broad spectrum of x-ray energy. And even though our energy level was slightly above the ideal absorption energy for sulfur, it generated the anomalous signals we needed.”

    But the scientists still had some work to do to extract those important signals and assemble the data from many tiny crystals.

    “We are actually getting thousands of pieces of data,” said Liu. “We used about 1400 microcrystals, each with its own data set. We have to put all the data from those microcrystals together.”

    4
    Scientists used a five-micron x-ray beam at the FMX beamline at NSLS-II to scan the entire grid and locate the tiny invisible crystals. Then a heat map (green) was used to guide the selection of positions for diffraction data acquisition.

    They also had to weed out data from crystals that were damaged by the intense x-rays or had slight variations in atomic arrangements.

    “A single microcrystal does not diffract x-rays sufficiently for structure solution prior to being damaged by the x-rays,” said Sean McSweeney, deputy photon division director and program manager of the Structural Biology Program at NSLS-II. “This is particularly true with crystals of only a few microns, the size of about a bacterial cell. We needed a way to account for that damage and crystal structure variability so it wouldn’t skew our results.”

    They accomplished these goals with a sophisticated multi-step workflow process that sifted through the data, discarded outliers that might have been caused by radiation damage or incompatible crystals, and ultimately extracted the anomalous scattering signals.

    “This is a critical step,” said Liu. “We developed a computing procedure to assure that only compatible data were merged in a way to align the individual microcrystals from diffraction patterns. That gave us the required signal-to-noise ratios for structure determination.”

    Applying the technique

    This technique can be used to determine the structure of any protein that has proven hard to crystallize to a large size. These include cell-surface receptors that allow cells of advanced lifeforms such as animals and plants to sense and respond to the environment around them by releasing hormones, transmitting nerve signals, or secreting compounds associated with cell growth and immunity.

    “To adapt to the environment through evolution, these proteins are malleable and have lots of non-uniform modifications,” said Liu. “It’s hard to get a lot of repeat copies in a crystal because they don’t pack well.”

    In humans, receptors are common targets for drugs, so having knowledge of their varied structures could help guide the development of new, more targeted pharmaceuticals.

    But the technique is not restricted to just small crystals.

    “The method we developed can handle small protein crystals, but it can also be used for any size protein crystals, any time you need to combine data from more than one sample,” Liu said.

    This research was supported in part by Brookhaven National Laboratory’s “Laboratory Directed Research and Development” program and the National Institutes of Health (NIH) grant GM107462. The NSLS-II at Brookhaven Lab is a DOE Office of Science user facility (supported by DE-SC0012704), with beamline FMX supported primarily by the National Institute of Health, National Institute of General Medical Sciences (NIGMS) through a Biomedical Technology Research Resource P41 grant (P41GM111244), and by the DOE Office of Science.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    BNL Campus


    BNL Center for Functional Nanomaterials

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 9:03 am on May 4, 2019 Permalink | Reply
    Tags: , , , Lisa Miller, NSLS-II,   

    From Brookhaven National Lab: Women n STEM- “Meet NSLS-II’s Lisa Miller” 

    From Brookhaven National Lab

    May 1, 2019
    Stephanie Kossman
    skossman@bnl.gov

    1
    As the manager of NSLS-II’s USCEO office, Lisa Miller can usually be found traveling around the facility’s experimental floor on trike—the most fun (and the safest) way to quickly get around NSLS-II’s half-mile ring.

    When Lisa Miller isn’t managing outreach efforts at the National Synchrotron Light Source II (NSLS-II) [image s below], she’s using the facility’s ultrabright x-ray light to study neurological protein-misfolding diseases, such as Alzheimer’s disease.

    Today, Miller is the manager of NSLS-II’s user services, communications, education, and outreach (USCEO) office, but she first came to the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory 25 years ago as a doctoral student at NSLS, the predecessor of NSLS-II—a DOE Office of Science User Facility at Brookhaven.

    “My thesis advisor came to NSLS all the time,” Miller said. “He would send a team of four students and we would spend a lot of time collecting each other’s data. I always got the night shift.”

    Having developed a passion for scientific collaboration and helping others collect their data, Miller decided to come back to NSLS for a postdoctoral research project—building an infrared beamline (experimental station) for biological research.

    2
    When Lisa Miller isn’t managing outreach efforts at NSLS-II, she’s using the facility’s ultrabright x-ray light to study neurological protein-misfolding diseases, such as Alzheimer’s disease.

    “And I’ve been here ever since,” she said. “After my postdoc, I ran two infrared beamlines at NSLS for 15 years.”

    Growing up, Miller and her three younger sisters were always encouraged to follow whatever career path they wanted. “Being a girl didn’t matter,” she said. “My dad taught us to drive a tractor, change the oil in the car, and fix the leaky sink. We got tools for our birthdays.”

    Of the four girls, Miller was the only one to become a scientist. “I always knew I liked science, but I never imagined working at a synchrotron light source,” she said. “I wanted to get a faculty job in a four-year undergraduate institution and teach. Research was a secondary thing to me. But in my early years at NSLS, I had such supportive mentors. All of the beamline scientists were so willing to help me succeed that, after a year, I had no desire to look for a faculty position.”

    During her time at NSLS and NSLS-II, Miller has been researching “protein-misfolding” diseases like Alzheimer’s disease, in which normal proteins in the brain clump together to form “plaques” and cause neurodegeneration—the death of brain cells.

    “We used the x-ray and infrared microscopes at NSLS to show that these plaques are loaded with metal ions like copper and zinc,” Miller said. “These metals are nutritionally essential, but they’re not supposed to be in the plaques. We’ve hypothesized that the metals can cause toxic reactions in the brain, leading to cell death. Now we are trying to figure out how and why this happens.”

    To move the field forward, Miller is developing new research methods that use the advanced capabilities of NSLS-II.

    “NSLS-II is a huge improvement for my research, especially in terms of the spatial resolution it provides,” she said. “Now we have these really tiny x-ray beams that enable us to image individual parts of the cells, including cell membranes, in order to understand how the metal ions are transported into the cells and damage them. The suite of imaging beamlines that we have here at NSLS-II enables us to study the problem from the level of the brain tissue all the way down to individual molecules in the cells.”

    Throughout her years of research, Miller retained her interest in science education. In 2001, she was asked to lead NSLS’s information and outreach office. Then, once NSLS-II was established, she became the facility’s first manager of USCEO.

    “Continuing my research is a really important part of my career, but that includes sharing my passion for science through teaching and outreach,” she said. As an adjunct associate professor in chemistry and biomedical engineering at Stony Brook University, Miller mentors doctoral students in synchrotron science. “Their generation will figure out the next cool things that synchrotrons can do.”

    Miller’s outreach efforts extend to the visiting researcher, or “user,” program that she oversees at NSLS-II.

    “My goal is for the users at NSLS-II to have a “Disneyland” user experience—to be able to do top-notch research, from conceiving the idea to doing the experiments and publishing the work, and having us support that. It’s more than just the photons; it’s everything from the registration process to comfortable accommodations and good coffee.”

    From the visiting researchers to the beamline scientists and support staff, Miller says having the chance to interact with so many different people is her favorite part of working at the light source.

    “We have a tremendous variety of personalities and a melting pot of people from all over the world,” she said. “The synchrotron community is a really welcoming and collaborative environment to be in.”

    As much as Miller likes working at NSLS-II, she stresses the importance of a work-life balance. Outside of “the office,” you can find Miller on backpacking trips around the country and the world. She’s hiked to the high points of 49 states, backpacked over 600 miles of the Appalachian Trail, and climbed Mount Kilimanjaro in Africa.

    Miller earned a Ph.D. in biophysics from Albert Einstein College of Medicine in 1995 and an M.S. in Chemistry from Georgetown University in 1992.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    BNL Campus


    BNL Center for Functional Nanomaterials

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 2:29 pm on April 26, 2019 Permalink | Reply
    Tags: "New Lens System for Brighter Sharper Diffraction Images", "The team used a photocathode gun that generates the electrons through a process called photoemission”, , “We made the sample by depositing the gold atoms on a several nanometer thick carbon film using a technique called thermal evaporation”, , Brookhaven’s Accelerator Test Facility, , Electron beam-related research techniques, , , NSLS-II, The researchers used two groups of four quadrupole magnets to tune the electron beam., Ultra-fast electron diffraction imaging   

    From Brookhaven National Lab: “New Lens System for Brighter, Sharper Diffraction Images” 

    From Brookhaven National Lab

    April 25, 2019

    Cara Laasch
    laasch@bnl.gov
    (631) 344-8458

    Peter Genzer
    genzer@bnl.gov
    (631) 344-3174

    Researchers from Brookhaven Lab designed, implemented, and applied a new and improved focusing system for electron diffraction measurements.

    1
    Mikhail Fedurin, Timur Shaftan, Victor Smalyuk, Xi Yang, Junjie Li, Lewis Doom, Lihua Yu, and Yimei Zhu are the Brookhaven team of scientists that realized and demonstrated the new lens system for as ultra-fast electron diffraction imaging.

    To design and improve energy storage materials, smart devices, and many more technologies, researchers need to understand their hidden structure and chemistry. Advanced research techniques, such as ultra-fast electron diffraction imaging can reveal that information. Now, a group of researchers from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have developed a new and improved version of electron diffraction at Brookhaven’s Accelerator Test Facility (ATF)—a DOE Office of Science User Facility that offers advanced and unique experimental instrumentation for studying particle acceleration to researchers from all around the world. The researchers published their findings in Scientific Reports, an open-access journal by Nature Research.

    Advancing a research technique such as ultra-fast electron diffraction will help future generations of materials scientists to investigate materials and chemical reactions with new precision. Many interesting changes in materials happen extremely quickly and in small spaces, so improved research techniques are necessary to study them for future applications. This new and improved version of electron diffraction offers a stepping stone for improving various electron beam-related research techniques and existing instrumentation.

    “We implemented our new focusing system for electron beams and demonstrated that we can improve the resolution significantly when compared to the conventional solenoid technique,” said Xi Yang, author of the study and an accelerator physicist at the National Synchrotron Light Source II (NSLS-II) [see below], a DOE Office of Science User Facility at Brookhaven Lab. “The resolution mainly depends on the properties of light – or in our case – of the electron beam. This is universal for all imaging techniques, including light microscopy and x-ray imaging. However, it is much more challenging to focus the charged electrons to a near-parallel pencil-like beam at the sample than it would be with light, because electrons are negatively charged and therefore repulse one another. This is called the space charge effect. By using our new setup, we were able to overcome the space charge effect and obtain diffraction data that is three times brighter and two times sharper; it’s a major leap in resolution.”

    2
    The colorful images are four different electron diffraction measurements at ATF. The left column shows diffraction patterns of the sample using the newly developed quadrupoles, while the right column shows diffraction patterns without the new lens system. In the left column the rings of the pattern are sharper, rounder and turn red, which means that the overall resolution of the measurement is higher.

    Every electron diffraction setup uses an electron beam that is focused on the sample so that the electrons bounce off the atoms in the sample and travel further to the detector behind the sample. The electrons create a so-called diffraction pattern, which can be translated into the structural makeup of the materials at the nanoscale. The advantage of using electrons to image this inner structure of materials is that the so called diffraction limit of electrons is very low, which means scientists can resolve smaller details in the structure compared to other diffraction methods.

    A diverse team of researchers was needed to improve such a complex research method. The Brookhaven Lab team consisted of electron beam experts from the NSLS-II, electron accelerator experts from ATF, and materials science experts from the condensed matter physics & materials science (CMPMS) department.

    “This advance would not have been possible without the combination of all our expertise across Brookhaven Lab. At NSLS-II, we have expertise on how to handle the electron beam. The ATF group brought the expertise and capabilities of the electron gun and laser technologies – both of which were needed to create the electron beam in the first place. And the CMPMS group has the sample expertise and, of course, drives the application needs. This is a unique synergy and, together, we were able to show how the resolution of the technique can be improved drastically,” said Li Hua Yu, NSLS-II senior accelerator physicist and co-author of the study.

    To achieve its improved resolution, the team developed a different method of focusing the electron beam. Instead of using a conventional approach that involves solenoid magnets, the researchers used two groups of four quadrupole magnets to tune the electron beam. Compared to solenoid magnets, which act as just one lens to shape the beam, the quadrupole magnets work like a specialized lens system for the electrons, and they gave the scientists far more flexibility to tune and shape the beam according to the needs of their experiment.

    “Our lens system can provide a wide range of tunability of the beam. We can optimize the most important parameters such as beam size, or charge density, and beam divergence based on the experimental conditions, and therefore provide the best beam quality for the scientific needs,” said Yang.

    The team can even adjust the parameters on-the-fly with online optimization tools and correct any nonuniformities of the beam shape; however, to make this measurement possible, the team needed the excellent electron beam that ATF provides. ATF has an electron gun that generates an extremely bright and ultrashort electron beam, which offers the best conditions for electron diffraction.

    “The team used a photocathode gun that generates the electrons through a process called photoemission,” said Mikhail Fedurin, an accelerator physicist at ATF. “We shoot an ultrashort laser pulse into a copper cathode, and when the pulse hits the cathode a cloud of electrons forms over the copper. We pull the electrons away using an electric field and then accelerate them. The amount of electrons in one of these pulses and our capability to accelerate them to specific energies make our system attractive for material science research – particularly for ultrafast electron diffraction.”

    The focusing system together with the ATF electron beam is very sensitive, so the researchers can measure the influences of Earth’ magnetic field on the electron beam.

    “In general, electrons are always influenced by magnetic fields—this is how we steer them in particle accelerators in the first place; however, the effect of Earth’s magnetic field is not negligible for the low-energy beam we used in this experiment,” said Victor Smalyuk, NSLS-II accelerator physics group leader and co-author of the study. “The beam deviated from the desired trajectory, which created difficulties during the initial starting phase, so we had to correct for this effect.”

    Beyond the high brightness of the electron beam and the high precision of the focusing system, the team also needed the right sample to make these measurements. The CMPMS group provided the team with a polycrystalline gold film to fully explore the newly designed lens system and to put it to the test.

    “We made the sample by depositing the gold atoms on a several nanometer thick carbon film using a technique called thermal evaporation,” said Junjie Li, a physicist in the CMPMS department. “We evaporated gold particles so that they condense on the carbon film and form tiny, isolated nanoparticles that slowly merge together and form the polycrystalline film.”

    This film was essential for the measurements because it has randomly oriented crystals that merge together. Therefore, the inner structure of the sample is not uniform, but consists of many differently oriented areas, which means that the diffraction pattern mainly depends on the electron beam qualities. This gives the scientists the best ground to really test their lens system, to tune the beam, and to see the impact of their tuning directly in the quality of the diffraction measurement.

    “We initially set out to improve electron diffraction for scientific studies of materials, but we also found that this technique can help us characterize our electron beam. In fact, diffraction is very sensitive to the electron beam parameters, so we can use the diffraction pattern of a known sample to measure our beam parameters precisely and directly, which is usually not that easy,” said Yang.

    The team intends to pursue further improvements, and they already have plans to develop another setup for ultra-fast electron microscopy to directly visualize a biological sample.

    “We hope to achieve ultrafast single-shot electron beam imaging at some point and maybe even make molecular movies, which isn’t possible with our current electron beam imaging setup,” said Yang.

    This research was supported by Laboratory Directed Research and Development funding and by DOE’s Office of Science through its support of the ATF.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    BNL Campus


    BNL Center for Functional Nanomaterials

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 6:44 pm on April 20, 2018 Permalink | Reply
    Tags: , , , Hard X-ray Nanoprobe, , New Capabilities at NSLS-II Set to Advance Materials Science, NSLS-II,   

    From BNL: “New Capabilities at NSLS-II Set to Advance Materials Science” 

    Brookhaven Lab

    The Hard X-ray Nanoprobe at Brookhaven Lab’s National Synchrotron Light Source II now offers a combination of world-leading spatial resolution and multimodal imaging.

    1
    Scientists at NSLS-II’s Hard X-ray Nanoprobe (HXN) spent 10 years developing advanced optics and overcoming many technical challenges in order to deliver world-leading spatial resolution and multimodal imaging at HXN.

    By channeling the intensity of x-rays, synchrotron light sources can reveal the atomic structures of countless materials. Researchers from around the world come to the National Synchrotron Light Source II (NSLS-II)—a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Brookhaven National Laboratory—to study everything from proteins to fuel cells. NSLS-II’s ultra-bright x-rays and suite of state-of-the-art characterization tools make the facility one of the most advanced synchrotron light sources in the world. Now, NSLS-II has enhanced those capabilities even further.

    Scientists at NSLS-II’s Hard X-ray Nanoprobe (HXN) beamline, an experimental station designed to offer world-leading resolution for x-ray imaging, have demonstrated the beamline’s ability to observe materials down to 10 nanometers—about one ten-thousandth the diameter of a human hair. This exceptionally high spatial resolution will enable scientists to “see” single molecules. Moreover, HXN can now combine its high spatial resolution with multimodal scanning—the ability to simultaneously capture multiple images of different material properties. The achievement is described in the Mar. 19 issue of Nano Futures.

    “It took many years of hard work and collaboration to develop an x-ray microscopy beamline with such high spatial resolution,” said Hanfei Yan, the lead author of the paper and a scientist at HXN. “In order to realize this ambitious goal, we needed to address many technical challenges, such as reducing environmental vibrations, developing effective characterization methods, and perfecting the optics.”

    A key component for the success of this project was developing a special focusing optic called a multilayer Laue lens (MLL)—a one-dimensional artificial crystal that is engineered to bend x-rays toward a single point.

    2
    A close-up view of the Hard X-ray Nanoprobe—beamline 3-ID at NSLS-II.

    “Precisely developing the MLL optics to satisfy the requirements for real scientific applications took nearly 10 years,” said Nathalie Bouet, who leads the lab at NSLS-II where the MLLs were fabricated. “Now, we are proud to deliver these lenses for user science.”

    Combining multimodal and high resolution imaging is unique, and makes NSLS-II the first facility to offer this capability in the hard x-ray energy range to visiting scientists. The achievement will present a broad range of applications. In their recent paper, scientists at NSLS-II worked with the University of Connecticut and Clemson University to study a ceramic-based membrane for energy conversion application. Using the new capabilities at HXN, the group was able to image an emerging material phase that dictates the membrane’s performance.

    “We are also collaborating with researchers from industry to academia to investigate strain in nanoelectronics, local defects in self-assembled 3D superlattices, and the chemical composition variations of nanocatalysts,” Yan said. “The achievement opens up exciting opportunities in many areas of science.”

    As the new capabilities are put to use, there is an ongoing effort at HXN to continue improving the beamline’s spatial resolution and adding new capabilities.

    “Our ultimate goal is to achieve single digit resolution in 3D for imaging the elemental, chemical, and structural makeup of materials in real-time,” Yan said.

    Scientific Paper: Multimodal hard x-ray imaging with resolution approaching 10 nm for studies in material science [IOP Science – Nano Futures]

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 11:15 am on March 31, 2017 Permalink | Reply
    Tags: , , Methanol, , NSLS-II   

    From BNL: “Chemists ID Catalytic ‘Key’ for Converting CO2 to Methanol” 

    Brookhaven Lab

    March 23, 2017
    Karen McNulty Walsh,
    (631) 344-8350
    kmcnulty@bnl.gov

    Peter Genzer
    (631) 344-3174
    genzer@bnl.gov

    Results will guide design of improved catalysts for transforming pollutant to useful chemicals.

    1
    Jingguang Chen and Jose Rodriguez (standing) discuss the catalytic mechanism with Ping Liu and Shyam Kattel (seated).

    Capturing carbon dioxide (CO2) and converting it to useful chemicals such as methanol could reduce both pollution and our dependence on petroleum products. So scientists are intensely interested in the catalysts that facilitate such chemical conversions. Like molecular dealmakers, catalysts bring the reacting chemicals together in a way that makes it easier for them to break and rearrange their chemical bonds. Understanding details of these molecular interactions could point to strategies to improve the catalysts for more energy-efficient reactions.

    With that goal in mind, chemists from the U.S. Department of Energy’s Brookhaven National Laboratory and their collaborators just released results from experiments and computational modeling studies that definitively identify the “active site” of a catalyst commonly used for making methanol from CO2. The results, published in the journal Science, resolve a longstanding debate about exactly which catalytic components take part in the chemical reactions—and should be the focus of efforts to boost performance.

    “This catalyst—made of copper, zinc oxide, and aluminum oxide—is used in industry, but it’s not very efficient or selective,” said Brookhaven chemist Ping Liu, the study’s lead author, who also holds an adjunct position at nearby Stony Brook University (SBU). “We want to improve it, and get it to operate at lower temperatures and lower pressures, which would save energy,” she said.

    But prior to this study, different groups of scientists had proposed two different active sites for the catalyst—a portion of the system with just copper and zinc atoms, or a portion with copper zinc oxide.

    “We wanted to know which part of the molecular structure binds and breaks and makes bonds to convert reactants to product—and how it does that,” said co-author Jose Rodriguez, another Brookhaven chemist associated with SBU.

    To find out, Rodriguez performed a series of laboratory experiments using well-defined model catalysts, including one made of zinc nanoparticles supported on a copper surface, and another with zinc oxide nanoparticles on copper. To tell the two apart, he used an energetic x-ray beam to zap the samples, and measured the properties of electrons emitted. These electronic “signatures” contain information about the oxidation state of the atoms the electrons came from—whether zinc or zinc oxide.

    2
    Brookhaven chemist Ping Liu

    Meanwhile Liu, Jingguang Chen of Brookhaven Lab and Columbia University, and Shyam Kattel, the first author of the paper and a postdoctoral fellow co-advised by Liu and Chen, used computational resources at Brookhaven’s Center for Functional Nanomaterials (CFN) and the National Energy Research Scientific Computing Center (NERSC)—two DOE Office of Science User Facilities—to model how these two types of catalysts would engage in the CO2-to-methanol transformations. These theoretical studies use calculations that take into account the basic principles of breaking and making chemical bonds, including the energy required, the electronic states of the atoms, and the reaction conditions, allowing scientists to derive the reaction rates and determine which catalyst will give the best rate of conversion.

    “We found that copper zinc oxide should give the best results, and that copper zinc is not even stable under reaction conditions,” said Liu. “In fact, it reacts with oxygen and transforms to copper zinc oxide.”

    Those predictions matched what Rodriguez observed in the laboratory. “We found that all the sites participating in these reactions were copper zinc oxide,” he said.

    But don’t forget the copper.

    “In our simulations, all the reaction intermediates—the chemicals that form on the pathway from CO2 to methanol—bind at both the copper and zinc oxide,” Kattel said. “So there’s a synergy between the copper and zinc oxide that accelerates the chemical transformation. You need both the copper and the zinc oxide.”

    3
    Ping Liu and Shyam Kattel with the x-ray source used in this study.

    Optimizing the copper/zinc oxide interface will become the driving principal for designing a new catalyst, the scientists say.

    “This work clearly demonstrates the synergy from combining theoretical and experimental efforts for studying catalytic systems of industrial importance,” said Chen. “We will continue to utilize the same combined approaches in future studies.”

    For example, said Rodriguez, “We’ll try different configurations of the atoms at the copper/zinc oxide interface to see how that affects the reaction rate. Also, we’ll be going from studying the model system to systems that would be more practical for use by industry.”

    An essential tool for this next step will be Brookhaven’s National Synchrotron Light Source II (NSLS-II), another Office of Science User Facility. NSLS-II produces extremely bright beams of x-rays—about 10,000 times brighter than the broad-beam laboratory x-ray source used in this study. Those intense x-ray beams will allow the scientists to take high-resolution snapshots that reveal both structural and chemical information about the catalyst, the reactants, and the chemical intermediates that form as the reaction occurs.

    3
    Brookhaven scientists identified how a zinc/copper (Zn/Cu) catalyst transforms carbon dioxide (two red and one grey balls) and hydrogen (two white balls) to methanol (one grey, one red, and four white balls), a potential fuel. Under reaction conditions, Zn/Cu transforms to ZnO/Cu, where the interface between the ZnO and Cu provides the active sites that allow the formation of methanol.

    “And we’ll continue to expand the theory,” said Liu. “The theory points to the mechanistic details. We want to modify interactions at the copper/zinc oxide interface to see how that affects the activity and efficiency of the catalyst, and we’ll need the theory to move forward with that as well.”

    An additional co-author, Pedro Ramírez of Universidad Central de Venezuela, made important contributions to this study by helping to test the activity of the copper zinc and copper zinc oxide catalysts.

    This research was supported by the DOE Office of Science.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: