Adjusting grain boundary within NiCo2O4 rod arrays by phosphating reaction for efficient hydrogen production. (11th June 2022)

• Record Type: Journal Article
• Authors: Ma, Xianguo; Wang, Zining; Wang, Zhihao; Cui, Mengqi; Wang, Hui; Ren, Jianwei; Karimzadeh, Sina
• Is Part Of: Nanotechnology. Volume 33:Number 24(2022)
• Publication Date: 2022-06-11
• Subjects: electronic structure -- grain boundary -- P-doped NiCo2O4 catalyst -- DFT calculation -- overall water splitting; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ac5ca3
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: In this work, the density and electronic structures of the metal active sites in NiCo2 O4 nanorod arrays were concurrently tuned by controlling the sample's exposure time in a phosphorization process. The results showed that both the density and electronic structure of the active adsorption sites played a key role towards the catalytic activity for water splitting to produce hydrogen. The optimal catalyst exhibited 81 mV overpotential for hydrogen evolution reaction (HER) at 10 mA cm −2 and 313 mV overpotential towards oxygen evolution reaction at 50 mA cm −2 . The assembled electrode delivered a current density of 50 mA cm −2 at 1.694 V in a fully functional water electrolyzer. The further results of theoretical density functional theory calculations revealed the doping of P elements lowered down the H adsorption energies involved in the water splitting process on the various active sites of P-NiCo2 O4 -10 catalyst, and thus enhanced its HER catalytic activities.