Self-supporting NiCo2O4 nanoneedle arrays on atomic-layer-deposited CoO nanofilms on nickel foam for efficient and stable hydrogen evolution reaction

作者：Pang, Ning; Tong, Xin; Deng, Yanping; Xiong, Dayuan^*; Xu, Shaohui; Wang, Lianwei^*; Chu, Paul K.

来源：MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 2023, 289: 116255.

DOI：10.1016/j.mseb.2022.116255

• Atomic layer deposition
• Nanoneedle arrays
• Nanofilms
• Hydrogen evolution reaction

Owing to easy recycling and the pollution-free nature of hydrogen fuel, electrochemical hydrogen production is attracting increasing attention. In this work, 3D NiCo2O4 nanoneedle arrays are prepared on porous nickel foam (NF) coated with a cobalt oxide nanofilm (CNF) produced by atomic layer deposition (ALD) to form a stable and robust catalyst for the hydrogen evolution reaction (HER). As a result, the optimized NiCo2O4@C12NF electrode exhibits excellent catalytic activity with a low overpotential of 96 mV versus RHE at a current density of 10 mA cm(-2), small Tafel slope of 50.6 mV dec-1, and outstanding stability for over 25 h in 1 M KOH. The excellent characteristics stem from synergistic effects of the unique nanoneedle arrays, abundant active sites, and short channels at the electrode-electrolyte interface. ALD is demonstrated to be a desirable technique to produce highly efficient HER electrocatalysts for commercial water electrolysis.