Regulating the electronic structure of ReS2 by Mo doping for electrocatalysis and lithium storage

Abstract

Transition metal sulfides have attracted increasing attention as promising electrode materials for electrochemical energy storage and conversion, including lithium-ion batteries and hydrogen evolution reaction. However, the electrochemical performance of most transition metal sulfides are greatly limited by their poor electronic conductivity. Regulating the electronic structure of transition metal sulfides through metal heteroatom doping is an effective strategy to solve this problem. Herein, we report an optimized Mo-doped rhenium disulfide nanosheets anchored on brush-like carbon arrays used as a bifunctional electrode material for lithium-ion batteries and hydrogen evolution reaction. Benefiting from the adjustment of the electronic structure of ReS2 by molybdenum doping, the as-synthesized material shows brilliant electrochemical performance. When used as a hydrogen evolution reaction electrocatalyst in acidic media, the optimized material demonstrates a low overpotential of 101 mV at −10 mA cm−2, a Tafel slope of 40 mV dec-1, and significantly enhanced durability. Furthermore, as an anode material for lithium-ion batteries, the electrode presents high specific capacity (1278 mAh g−1 at 0.1 A g−1) and excellent cyclability and rate capability (426 mAh g −1 at 5 A g−1). Based on the experimental tests and density functional theory analysis, the outstanding electrochemical performance of the as-synthesized electrode material was attributed to the rational construction of brush-like nanostructures and the molybdenum doping, resulting in improved electronic conductivity of rhenium disulfide. Hence, this composition regulating strategy based on metal atom doping can optimize the electrochemical performance of transition metal sulfides and offer a promising pathway to designing more efficientbifunctional electrode materials for lithium-ion batteries and hydrogen evolution reaction.