In situ modification of Cu substrate enables nickel-copper phosphide nanoarrays for enhanced electrocatalytic hydrogen evolution

Abstract

Searching for non-noble and high active electrocatalysts with excellent durability for hydrogen evolution reaction (HER) is significant for hydrogen production but remains a grand challenge. Here, we report a low-temperature oxidation strategy to modify copper foam (CF) and successfully built a heterogeneous NiP2-Cu3P nanoarray on the modified CF (NiCuP@CF), in which the CF functions as both conductive support and the precursor of the active substances. The resulting catalyst achieves low overpotentials of 113.4 and 266.4 mV to reach the current density of 10 and 100 mA cm−2 towards HER in alkaline electrolyte, respectively, benefiting from the 3D heterostructure arrays with abundant active sites and excellent conductivity. The open channels formed spontaneously in the 3D arrays allow rapid H2 bubbles to escape, which enables the catalyst to exhibit remarkable stability for at least 36 h under different current densities. This work presents a facile and economic modification method for Cu substrate, which will provide a good foundation for the subsequent material optimization, not limited to the heterogeneous metal phosphide catalyst toward HER.