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Recent advances in -synchrotron-based X-ray techniques are making it possible to address fundamental questions related to complex proton-coupled electron transfer reactions, for instance, the electrocatalytic water splitting process. However, it is still a grand challenge to assess the ability of the different techniques to characterize the relevant intermediates, with minimal interference on the reaction mechanism. To this end, we have developed a novel methodology employing X-ray photoelectron spectroscopy (XPS) in connection with the liquid-jet approach to probe the electrochemical properties of a model electrocatalyst, [Ru(bpy)(py)(OH)], in an aqueous environment. There is a unique fingerprint of the extremely important higher-valence ruthenium-oxo species in the XPS spectra along the oxidation reaction pathway. Furthermore, a sequential method combining quantum mechanics and molecular mechanics is used to illuminate the underlying physical chemistry of such systems. This study provides the basis for the future development of XPS techniques for water oxidation reactions.
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http://dx.doi.org/10.1021/acs.jpclett.9b02756 | DOI Listing |
ACS Appl Mater Interfaces
September 2025
National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
In this study, we analyze InO thin-film transistors (InO-TFT) using synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES) in conditions. A bottom-gate InO-TFT with a high- AlO gate dielectric, grown on thermally oxidized silicon (SiO/p-Si), was examined while operating at varying and . The results reveal that the In 3d core level binding energy varies along the horizontal channel length, driven by the potential gradient induced by .
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2025
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China; Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China. Electronic address:
The utilization of synergistic multivalent active sites holds potential in addressing the inherent sluggish kinetics of electrocatalytic reactions. Herein, we prepared au uNPs/Ni-NDC (NDC = 1,4-Naphthalenedicarboxylic acid) and leveraged the localized surface plasmon resonance (LSPR) effect to drive hot electron transfer from au nanoparticles to the Ni substrate, thereby generating multivalent active sites to boost the urea oxidation reaction (UOR). Under exciting light, au uNPs/Ni-NDC exhibited a twofold increase in UOR current accompanied by a significant negative shift in onset potential.
View Article and Find Full Text PDFInorg Chem
September 2025
Laboratoire de Chimie Physique Matière et Rayonnement (LCPMR), CNRS UMR 7614, Sorbonne Université (SU), 4 place Jussieu, Paris 75005, France.
The one-photon KV X-ray photoelectron spectra of Na and its hydrated clusters [Na(HO)] ( = 1-6) are dominated by the unusual 1s → 1s3s transition. KV spectroscopy also reveals a pronounced redistribution of the 1s → 1s3p transition cross sections, directly correlated with hydration number and molecular arrangement. Its intrinsic two-step nature, involving simultaneous core ionization and core excitation, enables detailed investigation of solvation-induced electronic structure changes, including dipole-forbidden excitations, core-valence charge transfer, and subtle 1s → V energy shifts.
View Article and Find Full Text PDFDiscov Nano
September 2025
Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Integrated Circuit, Ministry of Education, School of Physics, Zhengzhou University, Zhengzhou, 450052, China.
A cost-effective and large-scale method for synthesizing ZnCoO nanoflowers with surface oxygen vacancies as electrode materials for supercapacitors is presented. The existence of oxygen vacancies on the surface of the ZnCoO nanoflowers has been confirmed through X-ray photoelectron spectroscopy (XPS). The energy bands and density of states (DOS) of ZnCoO are examined using density functional theory, revealing that treatment with NaBH reduces the band gap of ZnCoO while increasing the DOS near the Fermi level compared to pristine ZnCoO.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Kathleen Lonsdale Materials Chemistry, Department of Chemistry, University College London, London WC1H 0AJ, U.K.
The exceptional performance of ceria (CeO) in catalysis and energy conversion is fundamentally governed by its defect chemistry, particularly oxygen vacancies. The formation of each oxygen vacancy (V) is assumed to be compensated by two localized electrons on cations (Ce). Here, we show by combining theory with experiment that while this 1 V: 2Ce ratio accounts for the global charge compensation, it does not apply at the local scale, particularly in nanoparticles.
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