Hierarchical Cu@Co-decorated CuO@Co3O4 nanostructure on Cu foam as efficient self-supported catalyst for hydrogen evolution reaction

Highlights: : • Cu/CuO@Co/Co₃O₄ samples were synthesized by a simple three-step reaction process. • Cu/CuO@Co/Co₃O₄-300 exhibits remarkable HER with low Tafel slopes and durable performances. • This research provides a new method for designing efficient non-precious catalysts for hydrogen evolution reaction. -- Abstract: The hydrogen evolution reaction (HER) is significant to the development of next-generation electrochemical energy devices. The exploration for a non-noble metal catalyst for energy conversion to replace rare and expensive noble metals is fully necessary. Herein, a novel hierarchical Cu and Co-decorated CuO@Co₃O₄ nanorod-thorns structure is generated on the Cu foam (denoted as Cu/CuO@Co/Co₃O₄) and utilized as an efficient electrocatalyst for hydrogen evolution reaction (HER) in 1.0 M KOH electrolyte. The Cu/CuO@Co/Co₃O₄-300 electrode displays low overpotentials for HER (82 mV) electrocatalytic performance at the current density of 10 mA cm⁻² and low Tafel slopes of 48 mV dec^-1 are also achieved. Impressively, Cu/CuO@Co/Co₃O₄-300 can consecutively generate H₂ with of its initial performance after 35 h in 1.0 M KOH electrolyte. Meanwhile, the electrochemical performance of Cu/CuO@Co/Co₃O₄-300 is superior or considerable to most of reported on Cu-based water splitting electrocatalysts. As evidenced, reduction of oxides to metal for electrocatalysts can remarkably raise the catalytic activities for hydrogen evolution reaction. In a word, this work affords a new thought to design efficient non-precious catalysts for hydrogen evolution reaction.