Optimization of the boosted photocatalytic H₂ production by rationally designated Cd_xZn_1-xS/MoS₂

Photocatalytic hydrogen production is a promising renewable energy process. CdS is a widely used photocatalyst; however, the photocorrosion problem causing the low stability and fast charge recombination problem causing the low photocatalytic activity are also well-known. To prevent the stability problem, CdxZn1-xS which has tunable optical properties has become forward. MoS2 is used as an additive to semiconductor photocatalysts due to its wide contact interface, inhibition of charge recombination, low cost, high reactivity for H-2 evolution reaction, and enhancement of visible light response. In this study, CdxZn1-xS/MoS2 was synthesized in an uniformly distributed nanocomposite form by solvothermal method using 1,3-diaminopropane for the first time. The characterization of the photocatalysts was performed with XRD, UV-vis DRS, TEM and electrochemical measurements. CdxZn1-xS/MoS2 photocatalysts were tested for hydrogen production under solar light. A full factor design was carried out via Minitab 19 to investigate the factors affecting the produced hydrogen amount. Cd/Zn ratio, MoS2 content, and photocatalyst loading were studied. Photocatalytic hydrogen production results were examined by analysis of variance and interpretation plots showed that the maximum hydrogen production would be obtained with 10 mg photocatalyst loading by CdxZn1-xS/MoS2 with Cd/Zn ratio between 0.5/0.5 and 0.7/0.3, and MoS2 content 2-4%.