Fe-Induced Surface Regulation and Accelerated Hydrogen Evolution Kinetics in γ-MnS Three-Dimensional Microarchitectures

Exploration of earth-abundant, efficient, nonprecious-metal electrocatalysts with promising hydrogen evolution kinetics is crucial for electrochemical water-splitting technology. In this study, we present a promising iron-doped manganese sulfide electrocatalyst consisting of three-dimensional microarchitecture surfaces that exhibit efficient hydrogen evolution activity in an alkaline electrolyte. Iron doping induces surface regulation in MnS promoting the growth of various morphologies from 3D microarchitectures to 2D sheets. The 3D architecture, coupled with abundant active sites and iron incorporation, promotes hydrogen adsorption in manganese sulfide. The influence of iron doping on the hydrogen evolution activity of manganese sulfide was systematically investigated. The Mn_0.95Fe_0.05S electrocatalyst, with optimized iron incorporation, demonstrated a low overpotential of 147 mV to achieve a current density of 10 mA cm^–2 in a 1 M KOH electrolyte. Post-hydrogen evolution reaction characterizations revealed Mn_0.95Fe_0.05S @FeMnOOH_xS_y, which were observed to be active catalysts enhancing the hydrogen evolution activity. This study presents an efficient strategy for Fe-induced 3D to 2D surface morphology modulation in MnS and offers an in-depth examination of its efficient electrochemical hydrogen evolution activity.