A corrosion-etching strategy for fabricating RuO2 coupled with defective NiFeZn(OH)x for a highly efficient hydrogen evolution reaction†

Developing cost-effective and durable hydrogen evolution reaction (HER) catalysts is imperative for electrochemical water splitting. Herein, a facile corrosion-etching strategy has been applied to synthesize RuO₂ coupled with defective NiFeZn(OH)_x on NiFe foam (NFF) at room temperature, achieving a D/NFF-Ru-Zn electrocatalyst with abundant structural defects. Benefiting from the abundant exposed defective sites and the synergistic effect between defective NiFeZn(OH)_x and RuO₂, D/NFF-Ru-Zn efficiently improves the poor intrinsic conductivity of NiFe hydroxide and reduces the kinetic energy barrier of the Volmer step, thus accelerating the HER kinetics. The prepared D/NFF-Ru-Zn catalyst demonstrates excellent activity with an overpotential of 90 mV at 100 mA cm^?2, as well as prominent durability of operating at 100 mA cm^?2 for 100 h. Furthermore, integrated with a NiFe-OH electrode, the assembled water splitting device displays a low voltage of 1.67 V at 500 mA cm^?2. Remarkably, the corrosion-etching strategy employed in this work can be extended to other substrates (e.g., Ni foam and Fe foam), providing a potential perspective for designing efficient HER electrocatalysts.