The dynamics of water molecules and the adsorption properties at the V and Y sites on the surface of the photocatalyst YVO(4) have been investigated by first principles molecular dynamics. This system has shown an excellent performance in the production of both hydrogen and oxygen in the ultraviolet region. Yet, its catalytic properties, related to the electronic structure, are poorly understood. Here we show that imperfectly oxygen coordinated V sites (i.e., not fourfold oxygen coordinated vanadium but threefold oxygen coordinated vanadium) exposed on the catalyst surface play a central role in the dissociation of water molecules. By simulating the H(2)O adsorption process and by performing an analysis of the electronic structure of the unoccupied orbitals corresponding to the lowest unoccupied energy level of the system, we can infer that the dissociation of water at these imperfectly oxygen coordinated V sites can promote the proton reduction and is expected to trigger the H(2) generation.
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http://dx.doi.org/10.1063/1.3170928 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Department of Biosphere Sciences and Engineering, Carnegie Institution for Science, Stanford, CA 94305.
Microbial mats are stratified communities often dominated by unicellular and filamentous phototrophs within an exopolymer matrix. It is challenging to quantify the dynamic responses of community members in situ as they experience steep gradients and rapid fluctuations of light. To address this, we developed a binary consortium using two representative isolates from hot spring mats: the unicellular oxygenic phototrophic cyanobacterium OS-B' (Syn OS-B') and the filamentous anoxygenic phototroph MS-CIW-1 (Chfl MS-1).
View Article and Find Full Text PDFBioconjug Chem
January 2025
Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
Silica nano/microparticles have generated significant interest for the past decades, emerging as a versatile material with a wide range of applications in photonic crystals, bioimaging, chemical sensors, and catalysis. This study focused on synthesizing silica nano/microparticles ranging from 20 nm to 1.2 μm using the Stöber and modified Stöber methods.
View Article and Find Full Text PDFCrit Rev Biochem Mol Biol
January 2025
Department of Chemistry, Emory University, Atlanta, GA, USA.
Mononuclear non-heme iron enzymes catalyze a wide array of important oxidative transformations. They are correspondingly diverse in both structure and mechanism. Despite significant evolutionary distance, it is becoming increasingly apparent that these enzymes nonetheless illustrate a compelling case of mechanistic convergence the formation of peroxo species bridging metal and substrate.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Donghua University, No.2999, North Renmin Road, Songjiang District, Shanghai, CHINA.
Herein, we demonstrate a two-in-one strategy for efficient neutral electrosynthesis of H2O2 via two-electron oxygen reduction reaction (2e-ORR), achieved by synergistically fine-modulating both the local microenvironment and electronic structure of indium (In) single atom (SA) sites. Through a series of finite elemental simulations and experimental analysis, we highlight the significant impact of phosphorous (P) doping on an optimized 2D mesoporous carbon carrier, which fosters a favorable microenvironment by improving the mass transfer and O2 enrichment, subsequently leading to an increased local pH levels. Consequently, an outstanding 2e-ORR performance is observed in neutral electrolytes, achieving over 95% selectivity for H2O2 across a broad voltage range of 0.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany.
Since water is both a product and a common reactant impurity in the (partial) methanol oxidation to methyl formate (MeFo) on gold, its effect on the isothermal selectivity to methyl formate was investigated under well-defined single-collision conditions employing pulsed molecular beam experiments and in situ IRAS measurements. Both a flat Au(111) and a stepped Au(332) surface were used as model catalysts to elucidate how water affects the reactivity of low-coordinated step sites as compared to (111) terrace sites employing a range of reaction conditions. The interactions of water with methanol/methoxy as well as with oxygen species are addressed.
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