Reconstruction of a surficial P-rich layer on Ni-P electrocatalysts for efficient hydrogen evolution applicable in acidic and alkaline media

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 457; p. 141138
• Main Authors: Jo, Seunghyun, Kang, Byeol, Oh, Hyunjun, Kwon, JunHwa, Choi, Pilsoo, Cho, Ki-Yeop, Lee, Joo-Hyoung, Eom, KwangSup
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2023
• Subjects: Electrocatalyst; Electroplating; Hydrogen evolution reaction; Nickel phosphide; Surface treatment; Hydrogen evolution reaction; Electrocatalyst; Electroplating; Surface treatment; Nickel phosphide
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.141138

[Display omitted] •Ni-P is a promising catalytic material for the hydrogen evolution reaction (HER).•The best catalytic activity can be achieved by controlling the surficial P ratio in Ni-P.•Here, we propose a facile surface-treatment based on dealloying by multiple CV cycles.•The suitably cycled Ni-Ps show the best catalytic performances in each acid and alkali media.•The different optimal cycle conditions in both media come from different RDSs. Ni-P is a promising catalytic material for the hydrogen evolution reaction (HER) due to its high catalytic activity, highly competitive cost, and practical usefulness. To achieve the best catalytic performance with the Ni-P-based material, it is necessary to control the P ratio in Ni-P because the catalytic kinetics of Ni-P depend on the number of reaction sites of the positively and negatively charged Ni and negatively charged P to adsorb the hydride/hydroxide and proton in acidic and alkaline media. Here, we introduce a facile surface-treatment based on dealloying to control the surficial P ratio with multiple CV cycles. As a result, the 20 and 10 times cycled Ni-P/CFPs show improved catalytic activities of 30.8% and 23.5% along with higher stabilities of 99.8 and 97.9% retention in acid and alkaline media, respectively. In particular, the different kinetics according to P ratio in both acid and alkaline media can be elucidated by DFT calculations of the free energy changes related to each RDS.