Simple one-step hydrothermal preparation of Mn–NiS2 for hydrogen evolution in alkaline environments†

Transition metal sulfides (TMS) have garnered increasing attention in recent years as promising alternatives to traditional noble metal-based electrocatalysts for hydrogen evolution. In this paper, Mn–NiS₂ nanocomposites were synthesized via a one-step hydrothermal method. The incorporation of manganese into transition metal sulfides improved the surface active area and conductivity of the nanoparticles, creating additional hydrogen evolution sites and enhancing their catalytic performance. The results showed that the Mn_0.5–NiS₂ electrode exhibited good catalytic performance and stability in alkaline environments. Mn_0.5–NiS₂ electrode showed an overpotential of only 111 mV at a current density of 100 mA cm⁻² (η₁₀₀ = 111 mV), while it could be operated stably for 100 h at a constant voltage density of 100 mV cm⁻². This work provides a simple and feasible approach for electrocatalytic materials for effective hydrogen evolution in alkaline environments.