LAUSR

The highly active bifunctional electrocatalysts for water splitting is of particular importance for the widespread usage of renewable energy, which require synergistic effect of ingenious architecture and intrinsic catalytic activity. Herein, we synthesized a novel Cu-Co-Se nanotube array supported on 3D copper skeleton as high-efficiency bifunctional electrocatalyst for overall water splitting via a facile two-step hydrothermal method. The rational designed CuCo-Se nanotube electrocatalyst exhibits good electrocatalytic performance, with only overpotential of 152 mV to generate 10 mA cm -2 for the HER while a small overpotential of 332 mV to drive a current density of 50 mA cm -2 for the OER process. The as-revealed good electrocatalytic performance is mainly due to the large electrochemical surface areas and electronic coupling synergies triggered by quantities of self-supported bimetallic nanotube architecture. The water-splitting system assembled using Cu-Co-Se nanotube as cathode and anode only needs a cell voltage of 1.65 V to drive current density of 10 mA cm -2 with long durability of 50 h for overall water splitting. Furthermore, the DFT calculation proves that the existence of electron exchange between the neighboring bi-metals as well as the coupling between Cu, Co and Se assembles contribute to the improvement of the water splitting performance. This work provides a general strategy to develop cost-efficient and geometrically-superior bimetallic electrocatalysts toward water splitting for large-scale hydrogen production.