Cobalt-molybdenum disulfide supported on nitrogen-doped graphene towards an efficient hydrogen evolution reaction

Herein, the cobalt-molybdenum bimetallic sulfide catalysts supported on nitrogen-doped graphene (CoMoS2/NGO) were facilely synthesized by a one-pot hydrothermal route. These composites exhibit various special nanostructures, rich in abundant edge site exposure and defects, which play an important role in providing active sites for catalyzing hydrogen evolution reaction (HER). When hydrogen peroxide (H2O2) was used as an additive in hydrothermal process, the as-fabricated composite exhibited more efficiency towards HER, showing as low onset overpotential (ηon) as −54 mV in 0.5 M H2SO4. Typical H2O2-assisted composite realized a remarkable cathodic current density of 30 mA cm−2 at an overpotential η = −137 mV and it possessed a small Tafel slope of 34.13 mV dec−1. Moreover, it exhibited an excellent cycling stability and superior electronic exchange rate. The results prove that CoMoS2/NGO catalysts have great potential for electrochemical HER.