Watching molecules in a light-triggered catalyst ring ‘like an ensemble of bells’

A better understanding of these systems will aid in developing next-generation energy technologies.

Photocatalysts ­– materials that trigger chemical reactions when hit by light – are important in a number of natural and industrial processes, from producing hydrogen for fuel to enabling photosynthesis.
Now an international team has used an X-ray laser at the Department of Energy’s SLAC National Accelerator Laboratory to get an incredibly detailed look at what happens to the structure of a model photocatalyst when it absorbs light.
The researchers used extremely fast laser pulses to watch the structure change and see the molecules vibrating, ringing “like an ensemble of bells,” says lead author Kristoffer Haldrup, a senior scientist at Technical University of Denmark (DTU). This study paves the way for deeper investigation into these processes, which could help in the design of better catalysts for splitting water into hydrogen and oxygen for next-generation energy technologies.
“If we can understand such processes, then we can apply that understanding to developing molecular systems that do tricks like that with very high efficiency,” Haldrup says.

>Read more on the Linac Coherent Light Source at SLAC website

Image: When photocatalyst molecules absorb light, they start vibrating in a coordinated way, like an ensemble of bells. Capturing this response is a critical step towards understanding how to design molecules for the efficient transformation of light energy to high-value chemicals.
Credit: Gregory Stewart/SLAC National Accelerator Laboratory

A series of stories celebrating the periodic table’s 150th anniversary

The ESRF is celebrating the International Year of the Periodic Table, because its elements are omnipresent in the research done at the facility. We will publish a series of stories on different elements during the coming weeks. The first series is about the fascinating elements at the bottom of the periodic table.

See the series start here on the ESRF website

Image: Kristina Kvashnina in front of the periodic table. She is from the Helmoltz-Zentrum Dresden-Rossendorf (HZDR) but based at the Rossendorf Beamline (BM20) of ESRF in Grenoble.
Credits: Moulyneux

Single atoms can make more efficient catalysts

Detailed observations of iridium atoms at work could help make catalysts that drive chemical reactions smaller, cheaper and more efficient.

Catalysts are chemical matchmakers: They bring other chemicals close together, increasing the chance that they’ll react with each other and produce something people want, like fuel or fertilizer.

Since some of the best catalyst materials are also quite expensive, like the platinum in a car’s catalytic converter, scientists have been looking for ways to shrink the amount they have to use.

Now scientists have their first direct, detailed look at how a single atom catalyzes a chemical reaction. The reaction is the same one that strips poisonous carbon monoxide out of car exhaust, and individual atoms of iridium did the job up to 25 times more efficiently than the iridium nanoparticles containing 50 to 100 atoms that are used today.

>Read more on the SSRL at SLAC website

Image: Scientists used a combination of four techniques, represented here by four incoming beams, to reveal in unprecedented detail how a single atom of iridium catalyzes a chemical reaction.
Credit: Greg Stewart/SLAC National Accelerator Laboratory

Improving lithium-ion battery capacity

Toward cost-effective solutions for next-generation consumer electronics, electric vehicles and power grids.

The search for a better lithium-ion battery—one that could keep a cell phone working for days, increase the range of electric cars and maximize energy storage on a grid—is an ongoing quest, but a recent study done by Canadian Light Source (CLS) scientists with the National Research Council of Canada (NRC) showed that the answer can be found in chemistry.
“People have tried everything at an engineering level to improve batteries,” said Dr. Yaser Abu-Lebdeh, a senior research officer at the NRC, “but to improve their capacity, you have to play with the chemistry of the materials.”

>Read more on the Canadian Light Source website

Image: The decomposition of a polyvinylidene fluoride (PVDF) binder in a high energy battery.
Credit: Jigang Zhou

Scientists produce 3-D chemical maps of single bacteria

Researchers at NSLS-II used ultrabright x-rays to generate 3-D nanoscale maps of a single bacteria’s chemical composition with unparalleled spatial resolution.

Scientists at 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—have used ultrabright x-rays to image single bacteria with higher spatial resolution than ever before. Their work, published in Scientific Reports, demonstrates an x-ray imaging technique, called x-ray fluorescence microscopy (XRF), as an effective approach to produce 3-D images of small biological samples.

“For the very first time, we used nanoscale XRF to image bacteria down to the resolution of a cell membrane,” said Lisa Miller, a scientist at NSLS-II and a co-author of the paper. “Imaging cells at the level of the membrane is critical for understanding the cell’s role in various diseases and developing advanced medical treatments.”
The record-breaking resolution of the x-ray images was made possible by the advanced capabilities of the Hard X-ray Nanoprobe (HXN) beamline, an experimental station at NSLS-II with novel nanofocusing optics and exceptional stability.
“HXN is the first XRF beamline to generate a 3-D image with this kind of resolution,” Miller said.

>Read more on the NSLS-II at Brookhaven National Laboratory website

Image: NSLS-II scientist Tiffany Victor is shown at the Hard X-ray Nanoprobe, where her team produced 3-D chemical maps of single bacteria with nanoscale resolution.

New clues to cut through the mystery of Titan’s atmospheric haze

A team including Berkeley Lab scientists homes in on a ‘missing link’ in Titan’s one-of-a-kind chemistry.

Saturn’s largest moon, Titan, is unique among all moons in our solar system for its dense and nitrogen-rich atmosphere that also contains hydrocarbons and other compounds, and the story behind the formation of this rich chemical mix has been the source of some scientific debate.
Now, a research collaboration involving scientists in the Chemical Sciences Division at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has zeroed in on a low-temperature chemical mechanism that may have driven the formation of multiple-ringed molecules – the precursors to more complex chemistry now found in the moon’s brown-orange haze layer.
The study, co-led by Ralf Kaiser at the University of Hawaii at Manoa and published in the Oct. 8 edition of the journal Nature Astronomy, runs counter to theories that high-temperature reaction mechanisms are required to produce the chemical makeup that satellite missions have observed in Titan’s atmosphere.

>Read more on the Advanced Light Source/Berkeley Lab website

Image: The atmospheric haze of Titan, Saturn’s largest moon (pictured here along Saturn’s midsection), is captured in this natural-color image (box at left). A study that involved experiments at Berkeley Lab’s Advanced Light Source has provided new clues about the chemical steps that may have produced this haze.
Credits: NASA Jet Propulsion Laboratory, Space Science Institute, Caltech

Single atoms break carbon’s strongest bond

Scientists discovered that single atoms of platinum can break the bond between carbon and fluorine, one of the strongest known chemical bonds.

An international team of scientists including researchers at Yale University and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have developed a new catalyst for breaking carbon-fluorine bonds, one of the strongest chemical bonds known. The discovery, published on Sept. 10 in ACS Catalysis, is a breakthrough for efforts in environmental remediation and chemical synthesis.

“We aimed to develop a technology that could degrade polyfluoroalkyl substances (PFAS), one of the most challenging pollutant remediation problems of the present day,” said Jaehong Kim, a professor in the department of chemical and environmental engineering at Yale University. “PFAS are widely detected all over the world, from Arctic biota to the human body, and concentrations in contaminated groundwater significantly exceed the regulatory limit in many areas. Currently, there are no energy-efficient methods to destroy these contaminants. Our collaboration with Brookhaven Lab aims to solve this problem by taking advantage of the unique properties of single atom catalysts.”

>Read more on the NSLS-II at Brookhaven National Laboratory website

Image: Brookhaven scientist Eli Stavitski is shown at NSLS-II’s Inner Shell Spectroscopy beamline, where researchers imaged the physical and chemical complexity of a single-atom catalyst that breaks carbon-fluorine bonds.

Using uranium to create order from disorder

The first demonstration of reversible symmetry lowering phase transformation with heating.

ANSTO’s unique landmark infrastructure has been used to study uranium, the keystone to the nuclear fuel cycle. The advanced instruments at the Australian Synchrotron and the Australian Centre for Neutron Scattering  have not only provided high resolution and precision, but also allowed in situ experiments to be carried out under extreme sample environments such as high temperature, high pressure and controlled gas atmosphere.

As part of his joint PhD studies at the University of Sydney and ANSTO, Gabriel Murphy has been investigating the condensed matter chemistry of a crystalline material, oxygen-deficient strontium uranium oxide, SrUO4-x, which exhibits the unusual property of having ordered defects at high temperatures.

“Strontium uranium oxide is potentially relevant to spent nuclear fuel partitioning and reprocessing,” said Dr Zhaoming Zhang, Gabriel’s ANSTO supervisor and a co-author on the paper with Prof Brendan Kennedy of the University of Sydney that was published recently in Inorganic Chemistry.
Uranium oxides can access several valence states, from tetravalent— encountered commonly in UO2 nuclear fuels, to pentavalent and hexavalent—encountered in both fuel precursor preparation and fuel reprocessing conditions.
Pertinent to the latter scenario, the common fission daughter Sr-90 may react with oxidised uranium to form ternary phases such as SrUO4.

>Read more on the Australian Synchrotron website

Image: Dr Zhaoming Zhang and Gabriel Murphy.

Graphene-Based Catalyst Improves Peroxide Production

Hydrogen peroxide is an important commodity chemical with a growing demand in many areas, including the electronics industry, wastewater treatment, and paper recycling.

Hydrogen peroxide (H2O2) is a common household chemical, well known for its effectiveness at whitening and disinfecting. It’s also a valuable commodity chemical used to etch circuit boards, treat wastewater, and bleach paper and pulp—a market expected to grow as demand for recycled paper products increases.

Compared to chlorine-based bleaches, hydrogen peroxide is more environmentally benign: the only degradation product of its use is water. However, it’s currently produced through a multistep chemical reaction that consumes significant amounts of energy, generates substantial waste, and requires a catalyst of palladium—a rare and expensive metal. Furthermore, the transport and storage of bulk hydrogen peroxide can be hazardous, making local, on-demand production highly desirable.

Better living through electrochemistry

Scientists seek a way to generate hydrogen peroxide electrochemically—by a much simpler process called the oxygen reduction reaction (ORR). This reaction takes oxygen from the air and combines it with water and two electrons to produce H2O2. If this reaction could be efficiently catalyzed, it could enable the disinfection of water at remote locations, or during disaster recovery, using hydrogen peroxide made from local air and water. For this work, the researchers focused on hydrogen peroxide synthesis in alkaline environments, where the reaction bath can be used directly, such as for bleaching or the treatment of acidic waste streams.

>Read more on the Advanced Light Source website

Image: The production of hydrogen peroxide (H2O2) from oxygen (O2) was efficiently catalyzed by graphene oxide, a form of graphene characterized by various oxygen defects that act as centers for catalytic activity. Depicted are two types of defects: one in which an oxygen atom bridges two carbon atoms above the graphene plane, and one where oxygen atoms replace carbon atoms within the graphene plane.

Research gives clues to CO2 trapping underground

CO2 is an environmentally important gas that plays a crucial role in climate change.

It is a compound that is also present in the depth of the Earth but very little information about it is available. What happens to CO2 in the Earth’s mantle? Could it be eventually hosted underground? A new publication in Nature Communications unveils some key findings.

Carbon dioxide is a widespread simple molecule in the Universe. In spite of its simplicity, it has a very complex phase diagram, forming both amorphous and crystalline phases above the pressure of 40 GPa. In the depths of the Earth, CO2 does not appear as we know it in everyday life. Instead of being a gas consisting of molecules, it has a polymeric solid form that structurally resembles quartz (a main mineral of sand) due to the pressure it sustains, which is a million times bigger than that at the surface of the Earth.

Researchers have been long studying what happens to carbonates at high temperature and high pressure, the same conditions as deep inside the Earth. Until now, the majority of experiments had shown that CO2 decomposes, with the formation of diamond and oxygen. These studies were all focused on CO2 at the upper mantle, with a 70 GPa of pressure and 1800-2800 Kelvin of temperature.

>Read more on the European Synchrotron (ESRF) website

Picture: Mohamed Mezouar, scientist in charge of ID27, on the beamline.
Credit: S. Candé. 

Research shows how to improve the bond between implants and bone

Research carried out recently at the Canadian Light Source (CLS) in Saskatoon has revealed promising information about how to build a better dental implant, one that integrates more readily with bone to reduce the risk of failure.

“There are millions of dental and orthopedic implants placed every year in North America and a certain number of them always fail, even in healthy people with healthy bone,” said Kathryn Grandfield, assistant professor in the Department of Materials Science and Engineering at McMaster University in Hamilton.

A dental implant restores function after a tooth is lost or removed. It is usually a screw shaped implant that is placed in the jaw bone and acts as the tooth roots, while an artificial tooth is placed on top. The implant portion is the artificial root that holds an artificial tooth in place.

Grandfield led a study that showed altering the surface of a titanium implant improved its connection to the surrounding bone. It is a finding that may well be applicable to other kinds of metal implants, including engineered knees and hips, and even plates used to secure bone fractures.

About three million people in North America receive dental implants annually. While the failure rate is only one to two percent, “one or two percent of three million is a lot,” she said. Orthopedic implants fail up to five per cent of the time within the first 10 years; the expected life of these devices is about 20 to 25 years, she added.

“What we’re trying to discover is why they fail, and why the implants that are successful work. Our goal is to understand the bone-implant interface in order to improve the design of implants.”

>Read more on the Canadian Light Source website

Synchrotron researchers uncover lost images from the 19th century

Art curators will be able to recover images on daguerreotypes, the earliest form of photography that used silver plates, after scientists learned how to use light to see through degradation that has occurred over time.

Research published today in Scientific Reports includes two images from the National Gallery of Canada’s photography research unit that show photographs that were taken, perhaps as early as 1850, but were no longer visible because of tarnish and other damage. The retrieved images, one of a woman and the other of a man, were beyond recognition. “It’s somewhat haunting because they are anonymous and yet it is striking at the same time,” said Madalena Kozachuk, a PhD student in the Department of Chemistry at Western University and lead author of the scientific paper.

“The image is totally unexpected because you don’t see it on the plate at all. It’s hidden behind time. But then we see it and we can see such fine details: the eyes, the folds of the clothing, the detailed embroidered patterns of the table cloth.”
The identities of the woman and the man are not known. It’s possible that the plates were produced in the United States, but they could be from Europe.
For the past three years, Kozachuk and an interdisciplinary team of scientists have been exploring how to use synchrotron technology to learn more about chemical changes that damage daguerreotypes.

>Read more on the Canadian Light Source (CLS) website

Image: A mounted daguerreotype resting on the outside of the vacuum chamber within the SXRMB (a beamline at CLS) hutch.
Credit: Madalena Kozachuk.

Berkeley Lab researchers receive DOE Early Career Research Awards

Six scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have been selected by the U.S. Department of Energy’s (DOE’s) Office of Science to receive significant funding for research through its Early Career Research Program.

The program, now in its ninth year, is designed to bolster the nation’s scientific workforce by providing support to exceptional researchers during the crucial early career years, when many scientists do their most formative work. The six Berkeley Lab recipients are among a total of 84 recipients selected this year, including 30 from DOE’s national laboratories. This year’s awards bring to 35 the total number of Berkeley Lab scientists who have received Early Career Research Program awards since 2010.

“We are grateful that DOE has chosen to recognize these six young Berkeley Lab scientists,” said Berkeley Lab Director Mike Witherell. “Our Lab takes very seriously the responsibility to train the next generation of scientists and engineers. Each of their proposed projects not only represents cutting-edge science but will also contribute to our understanding of the world and a sustainable future.“

The scientists are each expected to receive grants of up to $2.5 million over five years to cover year-round salary plus research expenses.

>Read more on the Advanced Light Source website

Image: Ethan Crumlin is a staff scientist at the Advanced Light Source (ALS), a DOE Office of Science User Facility at Berkeley Lab, who specializes in studies of chemistry at the interfaces between solids, liquids, and gases.

Molecular Anvils Trigger Chemical Reactions

Takeuchi Receives European Inventor Award 2018

Prolific patent-holder won for inventing battery that increases the lifespan of implantable defibrillators fivefold, greatly reducing need for reoccurring surgery.

Esther Sans Takeuchi, PhD, has won the 2018 European Inventor Award in the “Non-EPO countries”, the European Patent Office (EPO) announced today. The award was given to her by the EPO at a ceremony held today in Paris, Saint-Germain-en-Laye. Of the four U.S. scientists nominated for the award, Takeuchi is the only American to bring home Europe’s most prestigious prize of innovation.

Takeuchi is the Chief Scientist of the Energy Sciences Directorate at the U.S. Department of Energy’s Brookhaven National Laboratory, Stony Brook University’s (SBU) William and Jane Knapp Endowed Chair in Energy and the Environment, and a Distinguished Professor of Chemistry in the College of Arts & Sciences and in Materials Science and Chemical Engineering in the College of Engineering and Applied Sciences at SBU. She was honored for developing the compact batteries that power tiny, implantable cardiac defibrillators (ICDs)—devices that detect and correct irregular, potentially fatal, heart rhythms. Her lithium silver vanadium oxide (“Li/SVO”) battery extended the power-source lifetime for ICDs to around five years, considerably longer than its predecessors, thus reducing the number of surgeries patients needed to undergo to replace them. Her invention led not only to an advance in battery chemistry, but also enabled the production and widespread adoption of ICDs and significantly improved patient well-being.

>Read more on the National Synchrotron Light Source II (NSLS-II) website

Image: Esther Sans Takeuchi, a joint appointee of Brookhaven National Laboratory and Stony Brook University, has won the 2018 European Inventor Award in the category “Non-EPO countries.”

 

 

Perovskites, the rising star for energy harvesting

Perovskites are promising candidates for photovoltaic cells, having reached an energy harvesting of more than 20% while it took silicon three decades to reach an equivalent. Scientists from all over the world are exploring these materials at the ESRF.

Photovoltaic (PV) panels exist in our society since several years now. The photovoltaic market is currently dominated by wafer-based photovoltaics or first generation PVs, namely the traditional crystalline silicon cells, which take a 90% of the market share.

Although silicon (Si) is an abundant material and the price of Si-PV has dropped in the past years, their manufacturing require costly facilities. In addition, their fabrication typically takes place in countries that rely on carbon-intensive forms of electricity generation (high carbon footprint).

But there is room for hope. There is a third generation of PV: those based on thin-film cells. These absorb light more efficiently and they currently take 10% of the market share.

>Read more on the European Synchrotron website

Image: The CEA-CNRS team on ID01. From left to right: Peter Reiss, from CEA-Grenoble/INAC, Tobias Schulli from ID01, Tao Zhou from ID01, Asma Aicha Medjahed, Stephanie Pouget (both from CEA-Grenoble/INAC) and David Djurado, from the CNRS. 
Credits: C. Argoud.