Ni2Se3−CuSex Heterostructure as a Highly Efficient Bifunctional Electrocatalyst for Urea‐Assisted Hydrogen Generation

Coupling urea oxidation reaction (UOR) with hydrogen evolution reaction (HER) is an attractive alternative anode reaction for electrochemical hydrogen generation with low energy consumption. However, the development of highly efficient bifunctional electrocatalysts is still a challenge. In this work, Ni2Se3−CuSex heterostructure was synthesized on copper foam (Ni3Se2@CuSex/CF) by electrodeposition accompanied by a selenization process. Benefiting from the abundant active sites, faster reaction kinetics, and modulated electronic structure, the self‐supporting Ni3Se2@CuSex/CF electrode exhibited superior catalytic performance. Extremely low overpotentials of 120 and 140 mV were achieved at the current density of 100 mA cm−2 for HER/UOR, respectively. Respectively, in HER||UOR coupled electrolyzer for H2 generation, the Ni3Se2@CuSex/CF||Ni3Se2@CuSex/CF delivered a low cell voltage of 1.49 V to reach a high current density of 100 mA cm−2 along with good stability, outperforming most of the other well‐developed materials to date. The rational design of coupled heterostructure as bifunctional electrodes is a promising approach for energy‐saving H2 production. Urea oxidation: A novel coupled heterostructure based on the Ni3Se2 and CuSex materials is prepared by a simple two‐step treatment. Due to the hierarchical coupled heterostructure and strong electron interactions, this kind of electrocatalyst achieves superior bifunctional performance for urea‐assisted hydrogen generation in alkaline medium.