A novel Zn0.5Cd0.5S/WO3·H2O S-scheme heterostructures with one-pot synthesis for significant photodegradation of toxic Cr (VI) and organic RhB pollutants: Kinetics, degradation mechanism and photocatalytic evaluation

The artificial-photosynthetic semiconductor composites have attracted tremendous attention with respect to their enhanced photocatalytic properties. Herein, we reported the facile synthesis of Zn _0.5Cd _0.5S/WO ₃·H ₂ O S-scheme photocatalyst via one-pot in situ hydrothermal strategy. Density Functional Theory (DFT) calculation was employed to reveal the S-scheme photogenerated electron transfer mechanism, and the subsequent experimental characterization further illustrated the path for electron-hole transfer and separation under the effect of S-scheme heterojunction. The mass of WO ₃·H ₂O accounted for Zn _0.5Cd _0.5S/WO ₃·H ₂ O 48 wt% (ZCSW48) was the best high-efficiency S-scheme photocatalyst displayed significant photocatalytic properties on pollution degradation, in detail, with the Cr (VI) photoreduction rate of 2.27 μmol·s ⁻¹·g ⁻¹ _cat. and the Rhodamine B (RhB) photooxidation rate of 0.38 μmol·min ⁻¹·g ⁻¹ _cat., respectively. The designed Zn _0.5Cd _0.5S/WO ₃·H ₂ O photocatalysts have integrated with the three aspects of photocatalytic efficiencies including the visible light response, prolonged photogenerated carrier lifetime and the sufficient surface active sites due to amount of surface defects, therefore, this work provides more insights into the utilization of green energy for environmental treatment by artificial structured semiconductors.