Valence modulation of transition metal oxides represents a highly effective approach in designing high-performance catalysts, particularly for pivotal applications such as the hydrogen evolution reaction (HER) in solar/electric water splitting and the hydrogen economy. Recently, there has been a growing interest in high-valence transition metal-based electrocatalysts (HVTMs) due to their demonstrated superiority in HER performance, attributed to the fundamental dynamics of charge transfer and the evolution of intermediates. Nevertheless, the synthesis of HVTMs encounters considerable thermodynamic barriers, which presents challenges in their preparation. Moreover, the underlying mechanism responsible for the enhancement in HVTMs still needs to be discovered. Hence, the universal synthesis strategies of the HVTMs are discussed, and direct Raman spectroscopic evidence for intermediates regulation is revealed to guide the further design of the HVTM electrocatalysts. This work offers new insights for facile designing of HVTMs electrocatalysts for energy conversion and storage through adjusting the reaction pathway.
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http://dx.doi.org/10.1016/j.jcis.2024.01.071 | DOI Listing |
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March 2025
Guangxi Novel Battery Materials Research Center of Engineering Technology, School of Physical Science and Technology, Guangxi University, Nanning, 530004, P. R. China.
To improve the capacity at a high rate and cycle stability of LiNiCoMnO (NCM811), a simple strategy is developed to synthesize the tungsten/niobium (W/Nb) co-doped cathode material. W/Nb co-doping remarkably reduced the system energy of single W- or single Nb-doping. The co-doping makes the material have a more stable structure, and inhibits the anisotropic volume change caused by H2↔H3 phase transition, thus maintaining the integrity of particles and preventing the formation of microcracks.
View Article and Find Full Text PDFChemSusChem
February 2025
School of Materials Science & Engineering, University of Jinan, Jinan, 250022, P. R. China.
Recently, Co-free Ni-rich cathodes have received extensive concerns as a competitive candidate for next-generation sustainable lithium-ion batteries (LIBs) due to their high-capacity/operation voltage merits and elimination of expensive Co component. However, it is extremely challenging to solve the issues involving their intrinsic chemo-mechanical instabilities triggered by anisotropic lattice stress and short cycle life. Herein, we rationally incorporate tiny quintuple high-valence cations to engineer an entropy-assisted LiNiMnNbWSbTaMoO (denoted as EL-N9-3) as a competitive cathode for LIBs.
View Article and Find Full Text PDFMater Horiz
February 2025
School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China.
Antiferroelectric (AFE) ceramics exhibit significant potential for diverse applications in pulsed power capacitors, chiefly owing to their electric field-induced AFE-ferroelectric (FE) phase transitions. However, their lower intrinsic breakdown strength (BDS) frequently results in dielectric breakdown prior to the field-induced phase transition, critically undermining their energy storage performance. Herein, we introduced a high-performance PbHfO (PHO)-based AFE ceramic developed through a defect engineering strategy that successfully reduced the concentration of oxygen vacancies within the ceramic non-equivalent substitution of Ta ions in a high valence state.
View Article and Find Full Text PDFJ Am Chem Soc
February 2025
Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Lanthanide ions are hard Lewis acids and usually form weak bonds with soft sulfur donors, which result in the supposed instability of their complexes with S-coordinating ligands. Compared with luminescent lanthanide complexes with hard nitrogen or oxygen donor ligands, the development of luminescent lanthanide complexes based on sulfur-donor ligands currently lags behind. In this work, two types of poly(mercaptoimidazolyl)borate ligands, one is tridentate and the other is tetradentate, were used for the design and synthesis of two series of novel S-coordinating cerium(III) (Ce(III)) complexes, which were found to be not only luminescent but also with moderate to surprisingly good stability in air.
View Article and Find Full Text PDFJ Colloid Interface Sci
April 2025
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, Guangxi, PR China; Chongzuo Key Laboratory of Comprehensive Utilization Technology of Manganese Resources, Guangxi Key Laboratory for High-value Utilization of Manganese Resources, College of Chemistry and Biological Engineering, Guangxi Minzu Normal University, Chongzuo 532200, Guangxi, PR China. Electronic address:
O3-type NaNiFeMnO (NFM) is considered as a promising cathode material for sodium-ion batteries (SIBs) due to its high theoretical energy density and low production cost. However, the applications of NFM are restricted owing to detrimental interfacial side reactions and phase evolution during cycling. Herein, a three-in-one modification strategy, including NaMoO coating, surface reconstruction from layered to spinel phase, and Mo doping, is proposed to design NFM.
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