A 3D binder-free AgNWs@NiMo/PU electrode for efficient hydrogen evolution reaction

Developing stable and efficient electrocatalysts for hydrogen evolution reaction is of great significance for the production of clean hydrogen energy from water splitting. In this work, 3D AgNWs@NiMo/PU electrode was obtained by electrodepositing NiMo alloy onto three-dimensional silver nanowires conductive substrate (3D AgNWs/PU) which was uniformly assembled on the surface of the skeleton of a polyurethane sponge (PU). 3D AgNWs/PU provides good electrolyte permeability, rich active site attachment points, good electronic conductivity and electrocatalytic synergy, which greatly improves the catalytic activity. In addition, 3D AgNWs@NiMo/PU electrode does not need to use adhesive in the process of hydrogen evolution, which can improve the hydrogen evolution performance and stability of the electrode. Specifically, the optimized electrode (AgNWs@NiMo/PU-1200 s) exhibits excellent hydrogen evolution performance by achieving a low overpotential of 32 mV (vs. RHE) at a current density of 10 mA cm⁻², with a Tafel slope of 72 mV dec^-1 (in 1 M KOH). More interestingly, it also has good stability after 10 h of stability test. Therefore, this study provides a feasible way to develop stable and efficient 3D HER electrocatalysts.