Cu@Cu3 P Core-Shell Nanowires Attached to Nickel Foam as High-Performance Electrocatalysts for the Hydrogen Evolution Reaction.

The development of highly efficient and inexpensive electrocatalysts is of great importance for generating renewable energy. In this work, Cu@Cu3 P core-shell nanowires grown on nickel foam (Cu@Cu3 P/NF) are prepared by a novel in situ reduction of CuSO4 ⋅5 H2 O, which forms Cu, followed by surface oxidation and low-temperature phosphorization. The unique hierarchical architecture of Cu@Cu3 P/NF integrates the advantages of enlarged surface area, fast electron transport, numerous channels for gas rapid diffusion, non-polymer binder, and enhanced catalytic performance. Remarkably, Cu@Cu3 P/NF-50, with a molar ratio of Cu/Cu3 P of around 2.63, reveals a highly efficient catalytic performance for the hydrogen evolution reaction in alkaline solution with a Tafel slope of 59 mV dec-1 and a long durability of 48 h. Overpotentials as low as 218 and 302 mV are required to reach current densities of 10 and 100 mA cm-2 , respectively. Furthermore, the scientific understanding and design principle of Cu@Cu3 P/NF with controlled performance will encourage more research into other high-performance, low-cost electrocatalysts for renewable energy.