NEXAFS investigations of transition metal oxides, nitrides, carbides, sulfides and other interstitial compounds

Surface oxidation of pyrite under ambient atmospheric and aqueous (pH=2 to 10) conditions: Electronic structure and mineralogy from X-ray absorption spectroscopy

Bremsstrahlung Isochromat spectra of FeS2, NiS2 NiS1.2Se0.8 and NiSe2 are reported. These are the first direct experimental evidence for a sharp antibonding p-like state above the Fermi level. A comparison is made with experimental results in the literature. For FeS2 band structure calculations are also presented; these are in good agreement with experiment. The authors show that it is necessary in this calculation to include 'empty spheres' when using a muffin-tin approximation. This is because the pyrite crystal structure is far from close packed. Furthermore, they briefly discuss the electrical and magnetic properties of the compounds.

https://iopscience.iop.org/article/10.1088/0022-3719/20/26/015/pdf

Electronic structure of some 3D transition-metal pyrites

Catalysts with a single atom site allow highly tuning of the activity, stability, and reactivity of heterogeneous catalysts. Therefore, atomistic understanding of the pertinent mechanism is essential to simultaneously boost the intrinsic activity, site density, electron transport, and stability. Here, we report that atomically dispersed nickel (Ni) in zincblende cadmium-zinc sulfide quantum dots (ZCS QDs) delivers an efficient and durable photocatalytic performance for water splitting under sunlight. The finely tuned Ni atoms dispersed in ZCS QDs exhibit an ultrahigh photocatalytic H2 production activity of 18.87 mmol hour-1 g-1. It could be ascribed to the favorable surface engineering to achieve highly active sites of monovalent Ni(I) and the surface heterojunctions to reinforce the carrier separation owing to the suitable energy band structures, built-in electric field, and optimized surface H2 adsorption thermodynamics. This work demonstrates a synergistic regulation of the physicochemical properties of QDs for high-efficiency photocatalytic H2 production.

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Atomically dispersed Ni in cadmium-zinc sulfide quantum dots for high-performance visible-light photocatalytic hydrogen production

The new electrochemical reaction mechanism of Na/FeS2 cell at ambient temperature

Sulfur K X-Ray Absorption-Edge Structures and Electronic States of Transition-Metal Sulfides MS and MS2 (M = Fe, Co, Ni)

Analyse des spectres d'absorption RX de l'ion potassium dans dix sels mineraux et attribution des pics observes aux transitions aux etats lies et aux etats de continuum

C. Sugiura

Papers

Sulfur K X-Ray Absorption-Edge Structures and Electronic States of Transition-Metal Sulfides MS and MS2 (M = Fe, Co, Ni)

K-Edge X-Ray Absorption Spectra from Potassium Compounds