Stalactite-like Ni–Co–P/Cu3P heterostructures supported on Cu foam for enhanced alkaline hydrogen evolution reaction

Developing high-performance non-noble metal catalysts for the hydrogen evolution reaction (HER) is crucial for advancing alkaline water electrolysis as a sustainable hydrogen production technology. Herein, self-supported stalactite-like Ni–Co–P/Cu₃P–CF heterostructures are grown on Cu foam (CF) via in-situ growth, electrodeposition, and low-temperature phosphorization to maximize catalytic performance. In 1 M KOH, the Ni–Co–P/Cu₃P–CF catalyst achieves current densities of 10 mA cm⁻² and 100 mA cm⁻² at overpotentials of only 82 mV and 181 mV, respectively, along with a small Tafel slope of 54.9 mV dec⁻¹ and excellent stability (with merely a 2 mV overpotential loss after 60 h of testing). This is mainly attributed to the stalactite-like structure, which increases the exposure of active sites and facilitates the release of gas bubbles, coupled with the heterointerfaces combined with bimetallic electronic regulation that accelerates charge transfer and optimizes the adsorption energy of hydrogen evolution reaction intermediates. This study highlights the significance of structural design and bimetallic synergy in developing high-efficiency non-noble metal electrocatalysts, offering a highly promising approach for hydrogen production.