Category: ALS

Keeping Water-Treatment Membranes from Fouling Out

Keeping Water-Treatment Membranes from Fouling Out

When you use a membrane for water treatment, junk builds up on the membrane surface—a process called fouling—which makes the treatment less efficient. In this work, researchers studied how membranes are fouled by interactions between natural organic matter and positively charged ions (such as calcium cations) that are commonly found in water from dissolved minerals and salts.

“Fouling has been studied since membranes emerged for use in water purification decades ago, but it still remains one of the largest challenges in water treatment,” said the study’s first author, Matthew Landsman, an ALS collaborative postdoctoral fellow from the University of Texas at Austin’s Center for Materials for Water and Energy Systems (M-WET), a DOE Energy Frontier Research Center (EFRC). “Our research aimed to understand the molecular-level mechanisms that influence membrane fouling by natural organic matter so that we can establish design rules for making better membranes.”

After running laboratory fouling experiments on membranes at UT Austin, the team used synchrotron characterization techniques at the Advanced Light Source (ALS) and Brookhaven’s National Synchrotron Light Source II (NSLS-II) to analyze the surface and bulk compositions of the fouled membranes. At ALS Beamline 7.3.3, wide angle x-ray scattering (WAXS) was used to see if any inorganic contaminants, such as calcium carbonate, were precipitating on the membranes. At NSLS-II, soft and tender x-ray scattering experiments determined the distribution of calcium in the fouling layers.

Read more on the BNL website

Image: Top: Water-treatment facilities use arrays of cylindrical elements containing rolled-up membranes to filter contaminants from water. Bottom inset: In this experiment, such membranes were used to filter water containing ions (reddish spheres) and natural organic matter (green-brown blobs). The fouled membranes were analyzed using various x-ray probes, revealing (for example) how calcium cations form bridges between organic molecules, causing them to aggregate and reduce flow through the membrane.

How a record-breaking copper catalyst converts CO2 into liquid fuels

How a record-breaking copper catalyst converts CO2 into liquid fuels

Researchers at Berkeley Lab, collaborating with CHESS scientists at the PIPOXS beamline, have made the first real-time movies of copper nanoparticles as they evolve to convert carbon dioxide and water into renewable fuels and chemicals. Their new insights could help advance the next generation of solar fuels.

Since the 1970s, scientists have known that copper has a special ability to recycle carbon dioxide into valuable chemicals and fuels. But for many years, scientists have struggled to understand how this common metal works as an electrocatalyst, a mechanism that uses energy from electrons to chemically transform molecules into different products.

Now, a research team led by Lawrence Berkeley National Laboratory (Berkeley Lab) has gained new insight by capturing the world’s first real-time movies of copper nanoparticles (copper particles engineered at the scale of a billionth of a meter) as they convert CO2 and water into renewable fuels and chemicals: ethylene, ethanol, and propanol, among others. The work was reported in the journal Nature.

“This is very exciting. After decades of work, we’re finally able to show – with undeniable proof – how copper electrocatalysts excel in CO2 reduction,” said Peidong Yang, a senior faculty scientist in Berkeley Lab’s Materials Sciences and Chemical Sciences Divisions who led the study. Yang is also a professor of chemistry and materials science and engineering at UC Berkeley. “Knowing why copper is such an excellent electrocatalyst brings us steps closer to turning CO2 into new, renewable solar fuels through artificial photosynthesis.”

Read more on the CHESS website

Image: Artist’s rendering of a copper nanoparticle as it evolves during CO2 electrolysis: Copper nanoparticles (left) combine into larger metallic copper “nanograins” (right) within seconds of the electrochemical reaction, reducing CO2 into new multicarbon products.

Credit: Yao Yang/Berkeley Lab

More to life than light

More to life than light

The #LightSourceSelfies video campaign highlights the dedication and enthusiasm that is felt by those working in this field. To maintain a sense of physical and mental wellbeing, it is also important to make time for non-work related things like family, hobbies and interests. This montage, with contributors from the ESRF, ALS, MAX IV and Diamond, gives a flavour of the wide range of activities that those in the light source community enjoy when they are not working.

Nights!

Nights!

Experimental time at light sources is very precious. When a synchrotron or X-ray Free Electron Laser (XFEL) is in operating mode the goal is to allocate as many experimental shifts to external scientists and in-house research as possible. This includes night shifts! So, how do light source users survive the night shifts? #LightSourceSelfies brings you top tips from scientists based at, or using, 5 light sources in our collaboration – the ESRF, Advanced Light Source (ALS), ANSTO’s Australian Synchrotron, CHESS and the PAL XFEL.

A new approach creates an exceptional single-atom catalyst for water splitting

A new approach creates an exceptional single-atom catalyst for water splitting

Anchoring individual iridium atoms on the surface of a catalytic particle boosted its performance in carrying out a reaction that’s been a bottleneck for sustainable energy production.

A new way of anchoring individual iridium atoms to the surface of a catalyst increased its efficiency in splitting water molecules to record levels, scientists from the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University reported today.

It was the first time this approach had been applied to the oxygen evolution reaction, or OER ­–part of a process called electrolysis that uses electricity to split water into hydrogen and oxygen. If powered by renewable energy sources, electrolysis could produce fuels and chemical feedstocks more sustainably and reduce the use of fossil fuels. But the sluggish pace of OER has been a bottleneck to improving its efficiency so it can compete in the open market.

The results of this study could ease the bottleneck and open new avenues to observing and understanding how these single-atom catalytic centers operate under realistic working conditions, the research team said.

They published their results today in the Proceedings of the National Academy of Sciences.

Read more on the SLAC website

Image: An illustration depicts a new system developed at SLAC and Stanford that anchors individual iridium atoms to the surface of a catalyst, increasing its efficiency at splitting water to record levels. The eight-sided support structures, shaded in blue, each contain a single iridium atom (large blue spheres). The iridium atoms grab passing water molecules (floating above and to the left of them), and encourage them to react with each other, releasing oxygen molecules (above and to the right). This reaction, known as the oxygen evolution reaction or OER, plays a key role in producing sustainable fuels and chemicals.

Credit: Greg Stewart/SLAC National Accelerator Laboratory