This study investigates the effect of varying iron-to-nickel ratios on the catalytic performance of Fe-Ni oxide nanoparticles (NPs) for the oxygen evolution reaction (OER). Addressing the issue of high energy wastage due to large overpotentials in OER, we synthesized and characterized different NP catalysts with different Fe: Ni oxide ratios. Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD) were employed to determine the morphology, elemental and phase composition of the NPs. Furthermore, in-depth profiling with X-ray Photoelectron Spectroscopy (XPS) and Hard X-ray Photoelectron Spectroscopy (HAXPES) revealed that iron predominantly exists as oxide, while nickel exhibits both metallic and oxidic forms depending on the Fe content. XPS indicated an enrichment of iron at the NP surface, whereas HAXPES and EDS data agreed on the bulk stoichiometry. The assessment of the catalytic activity via cyclic voltammetry (CV) showed that the Fe: Ni ratio of 2:3 exhibited superior performance, characterized by lower overpotential and a smaller Tafel slope.
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http://dx.doi.org/10.1038/s41598-025-92720-3 | DOI Listing |
Adv Mater
March 2025
Key Laboratory of Light Energy Conversion Materials of Hunan Province College, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China.
Iridium-based electrocatalysts are commonly regarded as the sole stable operating acidic oxygen evolution reaction (OER) catalysts in proton-exchange membrane water electrolysis (PEMWE), but the linear scaling relationship (LSR) of multiple reaction intermediates binding inhibits the enhancement of its activity. Herein, the compressive strain and oxygen vacancy effect exists in iridium dioxide (IrO)-based catalyst by a doping engineering strategy for efficient acidic OER activity. In situ synchrotron characterizations elucidate that compressive strain can enhance Ir─O covalency and reduce the Ir─Ir bond distance, and oxygen vacancy (O) as an electronic regulator causes rapid adsorption of water molecules on the Ir and adjacent Ov (Ir─O) pair site to be coupled directly into O─O intermediates.
View Article and Find Full Text PDFCytometry B Clin Cytom
March 2025
Laboratoire d'Hématologie Biologique, Centre Hospitalier Universitaire de Limoges, Limoges, France.
Anticipating the evolution of septic patients with community-acquired pneumonia (CAP) is challenging for front-line physicians in the Emergency Department (ED). Prognosis depends mainly on early identification, antibiotics, organ support, but also immune status. The objective of this proof-of-concept study was to perform a cluster analysis to investigate whether specific phenotypes, including cellular immunology parameters, are associated with the prognosis in patients with CAP presenting to the ED.
View Article and Find Full Text PDFSci Rep
March 2025
Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, 12205, Berlin, Germany.
This study investigates the effect of varying iron-to-nickel ratios on the catalytic performance of Fe-Ni oxide nanoparticles (NPs) for the oxygen evolution reaction (OER). Addressing the issue of high energy wastage due to large overpotentials in OER, we synthesized and characterized different NP catalysts with different Fe: Ni oxide ratios. Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD) were employed to determine the morphology, elemental and phase composition of the NPs.
View Article and Find Full Text PDFWorld J Microbiol Biotechnol
March 2025
Department of Environmental Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia.
Agricultural practices such as conventional (CN) and conservation agriculture (CA) influence the composition and structure of soil microorganisms. We used short reads and genome-resolved metagenomic-based dual sequencing approaches to create a profile of bacterial and archaeal communities in hyperthermic Typic Haplustepts soil after seven years of CA and CN. The most differences in the physico-chemical and biological properties of soil were higher pH, organics carbon, available nitrogen and microbial biomass contents, activities of dehydrogenase, β-glucosidase, and arylsulfatase, found in CA soil.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2025
Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, PR China.
Dual-atom catalysts (DACs) are promising materials for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional electrocatalysts for rechargeable Zn-air batteries. Although there have been many theoretical studies of DACs, most of them assumed constant-charge conditions rather than the real electrochemical process of the constant-potential condition. In our work, we investigated Fe-based DACs for ORR and OER bifunctional catalytic performance by using constant-potential first-principles calculations.
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