LAUSR

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, Ni 2 Se 3 -CuSe x heterostructure is synthesized on copper foam (Ni 3 Se 2 @CuSe x /CF) by electrodeposition accompanied with a selenization process. Benefiting from the abundant active sites, faster reaction kinetics and modulated electronic structure, the self-supporting Ni 3 Se 2 @CuSe x /CF electrode exhibits superior catalytic performance. The extremely low overpotentials of 120 mV and 140 mV are achieved at the current density of 100 mA cm -2 for HER/UOR, respectively. Respectively, in HER||UOR coupled electrolyzer for H 2 generation, the Ni 3 Se 2 @CuSe x /CF||Ni 3 Se 2 @CuSe x /CF delivers a low cell voltage of 1.49 V to reach a high current density of 100 mA cm -2 along with good stability, which outperforms 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 H 2 production.