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Home / All items tagged with x-ray absorption spectroscopy (XAS)

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.

 

Multilayer Stack Opens Door to Low-Power Electronics

Researchers found that a multilayer stack of ultrathin materials exhibits a phenomenon called negative capacitance, which reduces the voltage required for transistor operation. The material is fully compatible with today’s silicon-based technology and is capable of reducing power consumption without sacrificing transistor size or performance. Read more »PPT-icon-35 PDF-icon-35

Jinghua Guo to Receive the 2022 Shirley Award

ALS senior scientist Jinghua Guo is the recipient of this year’s Shirley Award for Outstanding Scientific Achievement at the ALS. Guo is being recognized for pioneering the development of operando soft x-ray spectroscopy, work that’s enabled studies under realistic conditions, which is of great importance in environmental and energy research. Read more »

Operando Study of CO2 Reduction by Copper Nanoparticles

Since copper is necessary to catalyze the reduction of CO2, a greenhouse gas, to valuable products, scientists are working hard to improve its selectivity and activity. Now, researchers have developed an operando capability that can help in this effort by simultaneously probing chemical valence and interparticle dynamics. Read more »

Revealing Lithium Metal’s Electronic Structure

Spectroscopy at the ALS and theoretical calculations at the Molecular Foundry revealed the intrinsic spectroscopic signature of lithium metal and explained the origin of previous contradictory reports. The findings provide a benchmark for further studies of lithium compounds towards batteries with higher capacity and energy density. Read more »PPT-icon-35 PDF-icon-35

Synthesis of new two-dimensional titanium carbonitride Ti2C0.5N0.5Tx MXene and its performance as an electrode material for sodium-ion battery

Researchers report on the synthesis and characterization of a new 2D carbonitride MXene, Ti2C0.5N0.5. They explore the performance of this new MXene as electrode materials for sodium-ion batteries (SIBs). It outperformed its carbide counterpart (i.e., Ti2C) and all the other reports for multilayer MXenes in SIBs, and it showed a stable electrochemical performance over 500 cycles. Read more »

How Iron Remediates Arsenic in Groundwater

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 »

Interface Sensitivity in Electron/Ion Yield X-ray Absorption Spectroscopy: The TiO2–H2O Interface

To understand corrosion, energy storage, (electro)catalysis, etc., obtaining chemical information on the solid–liquid interface is crucial but remains extremely challenging. Here, x-ray absorption spectroscopy is used to study the solid–liquid interface between TiO2 and H2O. This result highlights the potential of electron-yield XAS to obtain chemical and structural information with a high sensitivity for the species at the electrode–electrolyte interface. Read more »