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Abstract Abundant transition metal borides are emerging as substitute electrochemical hydrogen evolution reaction (HER) catalysts for noble metals. Herein, an unusual canonic‐like behavior of theclattice parameter in the AlB2‐type solid solution Cr1–xMoxB2(x= 0, 0.25, 0.4, 0.5, 0.6, 0.75, 1) and its direct correlation to the HER activity in 0.5 M H2SO4solution are reported. The activity increases with increasingx, reaching its maximum atx= 0.6 before decreasing again. At high current densities, Cr0.4Mo0.6B2outperforms Pt/C, as it needs 180 mV less overpotential to drive an 800 mA cm−2current density. Cr0.4Mo0.6B2has excellent long‐term stability and durability showing no significant activity loss after 5000 cycles and 25 h of operation in acid. First‐principles calculations have correctly reproduced the nonlinear dependence of theclattice parameter and have shown that the mixed metal/B layers, such as (110), promote hydrogen evolution more efficiently forx= 0.6, supporting the experimental results.
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This content will become publicly available on May 13, 2026
Facile synthesis of cubic Ni1−xCrx nanoalloys and their composition-dependent electrocatalytic activity for the hydrogen evolution reaction
The viability of the electrolysis of water currently relies on expensive catalysts such as Pt that are far too impractical for industrial-scale use. Thus, there is considerable interest in developing low-cost, earth-abundant nanomaterials and their alloys as a potential alternative to existing standard catalysts. To address this issue, a synergistic approach involving theory and experiment was carried out. The former, based on density functional theory, was conducted to guide the experiment in selecting the ideal dopant and optimal concentration by focusing on 3d, 4d, and 5d elements as dopants on Ni (001) surface. Subsequently, a series of Ni1−xCrx(x= 0.01–0.09) alloy nanocrystals (NCs) with size ranging from 8.3 ± 1.6–18.2 ± 3.2 nm were colloidally synthesized to experimentally investigate the hydrogen evolution reaction (HER) activity. A compositional dependent trend for electrocatalytic activity was observed from both approaches with Ni0.92Cr0.08NCs showed the lowest ΔGHvalue and the lowest overpotential (η−10) at −10 mA cm−2current density (j), suggesting the highest HER activity among all compositions studied. Among alloy NCs, the highest performing Ni0.92Cr0.08composition displayed a mixed Volmer–Heyrovsky HER mechanism, the lowest Tafel slope, and improved stability in alkaline solutions. This study provides critical insights into enhancing the performance of earth-abundant metals through doping-induced electronic structure variation, paving the way for the design of high-efficiency catalysts for water electrolysis.
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- PAR ID:
- 10589840
- Publisher / Repository:
- IOP Science
- Date Published:
- Journal Name:
- Nanotechnology
- Volume:
- 36
- Issue:
- 22
- ISSN:
- 0957-4484
- Page Range / eLocation ID:
- 225401
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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