Three-Dimensional Dendritic Cu–Co–P Electrode by One-Step Electrodeposition on a Hydrogen Bubble Template for Hydrogen Evolution Reaction

A Cu–Co–P electrocatalyst for hydrogen evolution reaction (HER) was designed with a dendritic and porous foam structure. Fabricated by one-step electrodeposition with binary alloy on a hydrogen bubble template, the porous foam exhibited remarkable HER activity in alkaline conditions. Cu was the dominant element in the core and shell region and acted for 3D structure formation. Cu–Co formed in the shell part and acted as an active region for hydrogen evolution reaction. Also, as the amount of P increased in the Cu–Co–P foams, the pore numbers, the electrochemical surface area (ECSA), and the HER activity were enhanced. The improved activity is believed to originate from the charge separation between the negatively charged P (δ–) and positively charged Cu and Co (δ+), the larger ECSA, and increased porosity.