Ti@MoS_x core-shell nanowire arrays as self-supported electrodes for hydrogen evolution reaction

Amorphous molybdenum sulfide (MoS_x) is a promising catalyst for electrochemically producing hydrogen owing to its low cost, excellent catalytic activity, outstanding stability and ease of synthesis, however, the poor electrical conductivity restricts its hydrogen evolution activity. Herein, vertically standing Ti@MoS_x core-shell nanowire arrays (TMNs) are synthetized by an electrochemically assistant method. Then, the electrochemical properties of the TMNs in hydrogen evolution reaction are investigated, and the TMNs exhibit enhanced electrochemical properties. The onset overpotential is around 105 mV vs. reversible hydrogen electrode (RHE). The overpotential is 200 mV vs. RHE at 100 mA cm⁻², the Tafel slope is 76 mV decade⁻¹. We suggest the remarkable performances of the TMNs for HER can be attributed to the excellent conductivity supplied by the core-shell structure, the affluent mass transport channels provided by the array construction and the highly catalytic activity of S²⁻/S₂²⁻ edge sites.