A Self‐Standing High‐Performance Hydrogen Evolution Electrode with Nanostructured NiCo₂O₄/CuS Heterostructures

An efficient self‐standing 3D hydrogen evolution cathode has been developed by coating nickel cobaltite (NiCo 2 O 4 )/CuS nanowire heterostructures on a carbon fiber paper (CFP). The obtained CFP/NiCo 2 O 4 /CuS electrode shows exceptional hydrogen evolution reaction (HER) performance and excellent durability in acidic conditions. Remarkably, as an integrated 3D hydrogen‐evolving cathode operating in acidic electrolytes, CFP/NiCo 2 O 4 /CuS maintains its activity more than 50 h and exhibits an onset overpotential of 31.1 mV, an exchange current density of 0.246 mA cm −2 , and a Tafel slope of 41 mV dec −1 . Compared to other non‐Pt electrocatalysts reported to date, CFP/NiCo 2 O 4 /CuS exhibits the highest HER activity and can be used in HER to produce H 2 with nearly quantitative faradaic yield in acidic aqueous media with stable activity. Furthermore, by using CFP/NiCo 2 O 4 /CuS as a self‐standing electrode in a water electrolyzer, a current density of 18 mA cm −2 can be achieved at a voltage of 1.5 V which can be driven by a single‐cell battery. This strategy provides an effective, durable, and non‐Pt electrode for water splitting and hydrogen generation.