Studying impact of cobalt content on electrocatalytic activity of Cu-Co-P coating with dendrite-like architectures for hydrogen production

Abstract

The aim of this study was to enhance the electrocatalytic performance of the electrodeposited Cu-Co-P coating by adjusting the Co content. SEM images revealed that the presence of Co contributed to the formation of a nano/micro dendritic morphology. The electrocatalyst performance improved as the Co content increased. Specifically, the Cu-Co-P/60@NF electrode only required an overpotential of 102 mV (versus reversible hydrogen electrode (RHE)) at a current density of −10 mA/cm2. This electrode exhibited the lowest charge transfer resistance, promoting faster charge transfer at the electrocatalyst/electrolyte interface. The increase in electroactivity for the hydrogen evolution reaction (HER) with a higher Co content can be attributed to two factors: the construction of the porous nano/micro dendritic structure and the synergistic effect between P, Cu, and Co elements, which is influenced by their amounts in the coating. Moreover, this electrode demonstrated satisfactory stability for 14 hours of electrolysis at −100 mA/cm2. In a two-electrode system, it only required a cell voltage of 1.57 V to achieve a current density of 10 mA/cm2. As a result, the Cu-Co-P/60@NF electrode could hold promise as a cost-effective alternative to noble metal-based electrocatalysts.