(NiBi0.2)S-Decorated MoS2 composite electrocatalyst for stable hydrogen production via direct simulated seawater electrolysis

Direct seawater electrolysis offers a sustainable route for hydrogen production, but chloride ions cause side reactions and corrosion. Here, we report a heterogeneous (Ni,Bi)-doped MoS 2 electrocatalyst with staggered nanosheets grown on carbon cloth via one-step hydrothermal synthesis. The (NiBi 0.2 )S@MoS 2 catalyst achieves low overpotentials of 112 mV (pure water) and 114 mV (simulated seawater) at 10 mA cm −2 , with Tafel slopes of 61 and 69 mV dec −1 , respectively. It requires only 1.76 V to reach 100 mA cm −2 in two-electrode overall water splitting and operates stably for over 24 h in alkaline seawater. Bi doping promotes electron transfer from Ni and Mo to S sites, optimizing active center configuration, while heterogeneous interfaces enhance H 2 O dissociation and hydrogen chemisorption. This work provides insights for designing efficient, low-cost, and corrosion-resistant electrocatalysts for direct seawater splitting.