W-doped MoS2 nanosheets as a highly-efficient catalyst for hydrogen peroxide electroreduction in alkaline media

Abstract

Novel W-doped MoS₂ electrocatalysts have been successfully fabricated through a facile one-pot solvothermal method and employed for the hydrogen peroxide reduction reaction (HPRR) in emerging alkaline H₂O₂-based fuel cells. The wide composition stoichiometry of W-doped MoS₂ is obtained in molar fractions of 30% and 15%. It has been found that 30% W-doped MoS₂ presents superior catalytic activity with a high peak current density of 2.83 mA cm⁻² at −0.86 V vs. Hg/HgO, owing to the heteroatom doping and the defect sites that emerged in the nanostructure. Furthermore, the influence of alkali concentration, H₂O₂ concentration and temperature on the HPRR is systematically investigated. The mechanism of HPRR is illustrated using a rotating disk electrode as a direct two-electron electroreduction pathway. Thereby, a new insight into heteroatom doping in transition metal dichalcogenides for HPRR applications is provided.