Though iron has been demonstrated as an effective means to remediate arsenic contamination in groundwater, the mechanism was not well understood until now. For the first time, researchers have untangled the detailed steps of the interaction, informing more robust strategies for cleanup. Read more »
ALS Work Using XAS
In x-ray absorption spectroscopy (XAS), the incident x-ray energy is tuned over a range that will excite core-level electrons. Sharp increases in absorption occur at specific energies, characteristic of the absorbing element. The resulting spectra probe the elemental composition as well as the chemical and electronic structure of the material.
Trace Key Mechanistic Features of the Arsenite Sequestration Reaction with Nanoscale Zerovalent Iron
The advancing in situ XAS technique made it possible to uncover the As-nZVI reaction pathway, especially capturing transient reaction process at subsecond scale. Combining the in situ XAS experimental data with computational chemistry enabled the reaction steps to be verified, clarifying the unambiguous identification of the transit reactive intermediates. Read more »
A Two-Dimensional Room-Temperature Magnet
Researchers have made the world’s thinnest (one atom thick) magnet that’s chemically stable under ambient conditions. The two-dimensional material, magnetically characterized at the ALS, could enable big advances in next-generation memory devices, computing, spintronics, and quantum physics. Read more »
David Prendergast Wins 2021 Shirley Award
David Prendergast, an internationally recognized computational scientist whose first-principles calculations of x-ray spectra have helped with the interpretation of countless experiments done at the ALS, has been awarded the 2021 Shirley Award for Outstanding Scientific Achievement by the ALS Users’ Executive Committee. Read more »
Main Attraction: Scientists Create World’s Thinnest Magnet
A one-atom-thin 2D magnet that operates at room temperature could lead to new applications in computing and electronics—such as high-density, compact spintronic memory devices—and new tools for the study of quantum physics. X-ray experiments at the ALS characterized the material’s magnetic parameters under high temperature. Read more »
Scientists Uncover a Different Facet of Fuel-Cell Chemistry
Solid oxide fuel cells are a promising technology for cleanly converting chemical energy to electrical energy. To improve the efficiency of these devices, researchers studied a model electrode material in a new way—by exposing a different facet of its crystal structure to oxygen gas at operating pressures and temperatures. Read more »
2D MXene Shows Evidence of a Magnetic Transition
A variety of experiments, including ALS x-ray studies, provided direct evidence of a magnetic transition in a 2D compound called a MXene (pronounced “maxene”). The finding adds new functionality to a family of materials with numerous ways to fine-tune properties for applications ranging from spintronic devices to electromagnetic shielding. Read more »
Speeding Toward Improved Hydrogen Fuel Production
Researchers synthesized a material that speeds up one of the limiting steps in extracting hydrogen from alcohols. The catalyst cleanly and efficiently accelerates the removal of hydrogen atoms from a liquid chemical carrier. The material is robust, made from earth-abundant metals, and will help make hydrogen a viable energy source for a wide range of applications. Read more »
Scientists Design New Framework for Clean Water
A promising solution to water pollution from abandoned copper mines relies on materials that adsorb copper ions from wastewater, but commercially available products lack the required chemical specificity and load capacity. A team of scientists has designed a new crystalline material that targets and traps copper ions from wastewater with unprecedented precision and speed. Read more »
Understanding Electronic Structure in MXenes, One Atomic Layer at a Time
MXenes are 2D materials that can host a rich array of distinct chemical compositions that can be tuned for a broad range of applications, from energy storage to water purification. Site-specific x-ray absorption spectroscopy helped identify the unique roles of surface and subsurface transition-metal atoms in Ti-based MXenes. Read more »
- 1
- 2
- 3
- …
- 8
- Next Page »
