Boosted photo-electro-catalytic hydrogen evolution over the MoS2/MoO2 Schottky heterojunction by accelerating photo-generated charge kinetics

The photoelectrocatalytic water splitting of molybdenum disulfide is hindered by the intrinsic large electrical resistance among adjacent layers, serious photo-generated carrier recombination and limited utilization of visible light. Herein, we construct MoS2/MoO2 heterostructures via a facile in situ hydrothermal route, in which a Schottky junction is established between the MoS2 semiconductor and metallic MoO2. As a result, the photoelectrochemical current density of MoS2/MoO2 is enhanced about 1.6 times than that of pure MoS2, achieving −10.3 mA cm−2 at −1.8 V vs. SCE, which can be attributed to the reduced electron transfer resistance, enlarged photo-generated carrier separation efficiency and enhanced light absorption due to the presence of metallic MoO2.