Oxygen deficiency introduced Z-scheme CdS/WO3-x nanomaterials with MoS2 as cocatalyst towards enhancing visible-light-driven hydrogen evolution
Oxygen deficiency modified Z-scheme CdS/WO3-x nanohybrid with MoS2 as the cocatalyst was synthesized by microwave hydrothermal method and was used for photocatalytic hydrogen production under visible light irradiation. Loadings of WO3-x and MoS2 as well as the synthetic time of microwave-assisted hydrothermal process were optimized, the physicochemical and optical properties of the as-prepared photocatalysts were characterized by various techniques. Results showed that the material with 30 wt% of WO3-x, 0.1 wt% of MoS2 and preparation time of 120 minutes exhibited the most desirable morphology and structure for hydrogen production. The maximum hydrogen production of 2852.5 µmol/g/h was achieved, which was 5.5 times of pure CdS (519.1 µmol/g/h) and 1.5 times of CdS/30 wt% WO3-x (1879.0 µmol/g/h), and the external quantum efficiency (EQE) reached 10.0% at 420 nm. The improvement of photocatalytic performance could be attributed to the Z-scheme formed between CdS and WO3-x and MoS2 as an electron trap. It was worth mentioning that the size of composite had a negative correlation with H2 production rate.