Bubble-templated electrodeposition of bimetallic porous NiCo nanostructures as a high performance electrocatalyst for overall water splitting

The development of low-cost, efficient, and reproducible methods for preparing of electrocatalysts remains a major challenge in the pursuit of large-scale hydrogen production. In this study, we present a simple one-step bubble-templated electrodeposition method to fabricate NiCo alloy electrocatalysts with bifunctional properties for water electrolysis. By optimizing the Ni-to-Co ratio, a 3D porous dendritic nanosheet structure was achieved enhancing both charge transfer and gas release efficiency. Moreover, the synergistic effect between Ni and Co in the alloy further boosts the electrocatalytic performance for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). At a current density of 100 mA cm −2 , the electrocatalyst exhibited overpotentials of 236.3 mV for HER and 372.96 mV for OER. Additionally, the electrocatalysts exhibited excellent long-term operational stability, sustaining their performance for 300 h at 100 mA cm −2 and 450 h at 500 mA cm −2 without significant degradation, demonstrating outstanding long-term stability. This work provides a promising approach to streamline the preparation of high-performance catalysts, paving the way for their large-scale industrial applications.