Facile Construction of Ultrathin V-Doped NiSe2/Ni3Se4/CuSe Nanosheets for Enhanced Urea-Assisted Electrochemical Hydrogen Production

Hydrogen production by electrolytic water is a green technology, which is conducive to alleviating the current severe energy and environmental crisis. However, it is affected by the high oxygen evolution reaction (OER) potential and has high energy consumption. Replacing the OER with the urea oxidation reaction (UOR) can reduce energy consumption. Herein, V-doped bimetallic selenides with an ultrathin nanosheet structure catalyst (V–NiSe2/Ni3Se4/CuSe/NF) are prepared via hydrothermal and low-temperature selenization. The catalyst has excellent UOR activity with a low potential of 1.33 V at 100 mA cm–2 and remarkable stability (120 h at 10 mA cm–2). Electrochemical measurements and characterization indicate that the abundant interface formed by NiSe2/Ni3Se4 and CuSe can induce charge transfer, thereby improving the catalytic activity and stability of the electrode material. V doping promotes the formation of ultrathin nanosheets with folds, which favors expanding the catalyst's active site and the contact region between the catalyst and the electrolyte, thus improving the catalytic activity. In situ Raman measurement further proves that V doping is beneficial to the surface reconstruction of the catalyst and accelerates the reaction kinetics of UOR. This work offers a new idea for the preparation of highly active UOR electrodes.