P-doped MoS2/CoxSy heterojunction for high-efficiency electrocatalytic hydrogen evolution performance in both acidic and alkaline electrolytes

Abstract

It is still challenging for the development of highly efficient non-noble metal electrocatalysts toward hydrogen evolution reaction (HER). Herein, an unreported material constructing strategy of combining crystalline-amorphous hetero-interface and heteroatomic doping towards electrocatalytic HER is firstly presented. The authors fabricate a self-supported P-MoS2/CoxSy@C/CFP electrode consisting of P-doped crystalline-amorphous MoS2/CoxSy heterojunction in-situ grown on carbon fiber paper (CFP). Benefitting from the strong electronic interaction at the interface of crystalline MoS2 and amorphous CoxSy, the electronic structure of MoS2/CoxSy@C/CFP is optimized. Moreover, the P doping can further optimize the electronic structure and enhance water adsorption of the catalyst and lower the kinetic energy barrier of HER. The heterojunction P-MoS2/CoxSy@C/CFP can not only exhibit excellent HER activity in alkaline electrolyte but also in acidic electrolyte, with the relatively lower overpotentials of 59 mV and 135 mV at the current density of 10 mA cm−2 in 1 M KOH and 0.5 M H2SO4; 140 mV and 205 mV at the current density of 100 mA cm−2 in 1 M KOH and 0.5 M H2SO4, respectively, which the HER performance is among the best for non-precious metal-based electrocatalysts usable in both acidic and alkaline mediums. Theoretical calculations also confirm that the construction of crystalline-amorphous heterointerface between MoS2 and CoxSy and P doping can effectively accelerate the electron transport and promote the HER reaction kinetics, thus enhancing the HER performance. This construction strategy for HER electrocatalyst provides a new avenue on electrocatalytic research.