Controlled synthesis of bifunctional particle-like Mo/Mn-NixSy/NF electrocatalyst for highly efficient overall water splitting

Abstract

Heteroatom-doping engineering has been recognized as an effective strategy to improve the activity and stability of electrocatalytic materials. Herein, we fabricated a bimetallic Mo/Mn codoped three-phase nickel sulfide on Ni foam, with Mo/Mn-Ni_xS_y/NF successfully synthesized via hydrothermal synthesis and calcination. In order to better explore the codoping effect of Mo/Mn, we also synthesised Ni₃S₂/NF, NiS@Ni_0.96S/NF, Mo-Ni₃S₂/NF and Mn-NiS@Ni_0.96S/NF and their electrocatalytic activities (HER, OER, and overall water splitting) were systematically investigated. As expected, Mo/Mn-Ni_xS_y/NF catalysts exhibited excellent catalytic activities and long-term durability. High electrochemical performance of Mo/Mn-Ni_xS_y/NF exceeded that of most reported non-precious metal catalysts and also benchmark RuO₂, IrO₂ and Pt/C. Moreover, in order to better understand the catalytic process, three possible mechanisms were further proposed to rationalize the enhanced electrocatalytic performance. Our work might broaden the avenue to construct efficient non-precious bifunctional catalysts and further develop large-scale electricity-to-hydrogen applications.