Fe-Induced Surface\nRegulation and Accelerated Hydrogen\nEvolution Kinetics in γ‑MnS Three-Dimensional Microarchitectures

Exploration of earth-abundant, efficient, nonprecious-metal\nelectrocatalysts\nwith promising hydrogen evolution kinetics is crucial for electrochemical\nwater-splitting technology. In this study, we present a promising\niron-doped manganese sulfide electrocatalyst consisting of three-dimensional\nmicroarchitecture surfaces that exhibit efficient hydrogen evolution\nactivity in an alkaline electrolyte. Iron doping induces surface regulation\nin MnS promoting the growth of various morphologies from 3D microarchitectures\nto 2D sheets. The 3D architecture, coupled with abundant active sites\nand iron incorporation, promotes hydrogen adsorption in manganese\nsulfide. The influence of iron doping on the hydrogen evolution activity\nof manganese sulfide was systematically investigated. The Mn<sub>0.95</sub>Fe<sub>0.05</sub>S electrocatalyst, with optimized iron incorporation,\ndemonstrated a low overpotential of 147 mV to achieve a current density\nof 10 mA cm<sup>–2</sup> in a 1 M KOH electrolyte. Post-hydrogen\nevolution reaction characterizations revealed Mn<sub>0.95</sub>Fe<sub>0.05</sub>S @FeMnOOH<sub><i>x</i></sub>S<sub><i>y</i></sub>, which were observed to be active catalysts enhancing the\nhydrogen evolution activity. This study presents an efficient strategy\nfor Fe-induced 3D to 2D surface morphology modulation in MnS and offers\nan in-depth examination of its efficient electrochemical hydrogen\nevolution activity.