Hetero-coupling and photothermal effects co-modulated reaction kinetics for highly-efficient electrocatalytic hydrogen evolution reaction

MoS 2 is an important electroactive material with attractive prospect for hydrogen evolution reaction (HER) application, but limited number of active sites and electronic conductivity greatly hinder the improvement of its electrocatalytic performances. This work reports an innovative MoS 2 /Ag 2 S nanohybrids (NHs) with Ag 2 S nanoparticles anchored onto the surface of MoS 2 nanoflowers . Particularly, the Ag 2 S herein demonstrates strong electronic coupling effect with the MoS 2 matrix while the MoS 2 shows dominant photothermal effect, which greatly improve the number of electrochemical active sites and reaction kinetics of the MoS 2 /Ag 2 S NHs, respectively. Thus when applied to HER, the MoS 2 /Ag 2 S NHs show remarkable overpotential at 10 mA cm −2 (138 mV), Tafel slope (72 mV dec −1 ) and exchange current density (1.6 mA cm −2 ) under the irradiation of 808 nm light, superior than that of the MoS 2 , Ag 2 S counterparts and MoS 2 /Ag 2 S NHs without light irradiation . Such a hetero-coupling and photothermal effects co-modulated design strategy provides a new avenue and an alternative catalyst to Pt for HER and other-energy related applications.