Morphology-dependent quasi 2D/2D point-flat-plate ternary CdS/MoS2/WS2 heterojunction with improved visible photocatalytic degradation of tetracycline

The morphology of CdS affects its photocatalytic properties and assembly efficiency of CdS-based heterojunction. In this study, various morphologies of CdS, including sloping plate, spherical, flower, lamellar and leaf were synthesized by adjusting different solvents and crystal control agents in solvothermal process. By comparison of geometric matching and photocatalytic activity of the multi-shaped CdS assembling with MoS2, the concept of point-flat-plate microstructure assembly was firstly introduced into construction of ternary quasi 2D/2D CdS/ MoS2/WS2 heterojunction. Owing to better geometric configuration, quasi 2D/2D CdS/MoS2/WS2 hetero-junction exhibited excellent characteristics of photocatalytic degradation of tetracycline. In this work, 97.2% of tetracycline (20 mg/L, 0.1 g/L dosage) was degraded within 60 min under the irradiation of 150 W Xenon light power, which was superior to other previously reported CdS heterojunctions.The enhancement of photocatalytic performance was due to the faster separation of photogenerated electrons and the lower recombination of electron-hole pairs in point-flat-plate CdS/MoS2/WS2 heterojunction. This study provides a promising way to construct highly efficient photocatalyst and other micro-nano structures for different applications.