Anchoring nitrogen-doped Co2P nanoflakes on NiCo2O4 nanorod arrays over nickel foam as high-performance 3D electrode for alkaline hydrogen evolution

Effective and robust electrocatalysts are mainly based on innovative materials and unique structures. Herein, we designed a flakelike cobalt phosphide-based catalyst supporting on NiCo2O4 nanorods array, which in-situ grew on the nickel foam (NF) current collector, referring as N- Co2P/NiCo2O4/NF electrode. By optimizing the microstructure and electronic structure through 3D hierarchy fabrication and nitrogen doping, the catalyst features with abundant electrochemical surface area, favorable surface wettability, excellent electron transport, as well as tailored d band center. Consequently, the as-prepared N-Co2P/NiCo2O4/NF electrode exhibits an impressive HER activity with a low overpotentials of 58 mV at 10 mA cm -2, a Tafel slop of 75 mV dec-1, as well as superior durability in alkaline medium. This work may provide a new pathway to effectively improve the hydrogen evolution performance of transition metal phosphides and to develop promising electrodes for practical electrocatalysis.(c) 2023 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communi-cations Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Effective and robust electrocatalysts can be achieved through the design of innovative materials and unique structures. This study presents a flakelike cobalt phosphide-based catalyst supported on NiCo2O4 nanorods array, grown in-situ on a nickel foam current collector. The optimized microstructure and electronic structure of the catalyst contribute to its abundant electrochemical surface area, favorable surface wettability, excellent electron transport, and tailored d band center. The resulting N-Co2P/NiCo2O4/NF electrode exhibits impressive hydrogen evolution reaction activity with low overpotentials and superior durability in alkaline medium, indicating its potential for practical electrocatalysis applications.