Compositional regulation and modification of the host CdS for efficient photocatalytic hydrogen production: Case study on MoS2 decorated Co0.2Cd0.8S nanorods

Compositional regulation and modification of CdS are effective strategies to enhance its photocatalytic activity and stability. Herein, a series of MoS2 modified Co0.2Cd0.8S nanorods (CCS) was synthesized by a hydrothermal method and used for photocatalytic hydrogen evolution reaction (HER) under visible light irradiation. The results indicated that the HER activity and stability of CdS could be substantially improved by the introduction of Co2+ into CdS lattice, which can accelerate the separation of photoinduced charge carriers and avoid the formation of high oxidation power holes (h(+)) due to the upward shift of the valence band edge. The HER performance of CCS could be further enhanced by the decoration of MoS2 nanosheets. CCS loaded with 5% MoS2 (wt %) showed the highest activity (2835.6 mu mol.g(-1).h(-1)), which is about 8.9 and 1.6 times higher than that of CdS and CCS. The type II heterojunction formed between CCS and the intimately contacted MoS2 accounts for the improvement as MoS2 can serve as trapping centers for photoinduced electrons (e(-)) and active sites for HER. This work demonstrated that the activity and the stability of CdS for photocatalytic HER could be boosted by a consolidation of CoS with the host CdS to form a solid solution and a further decoration with low-cost MoS2 cocatalyst.