Innovation synthesis of Zn0.5Cd0.5S/WO3 S-scheme heterostructures with significantly enhanced photocatalytic activity

In our work, Zn 0.5 Cd 0.5 S/WO 3 (ZCSW) S-scheme heterostructure composites were prepared by an innovation synthesis called electrostatic adsorption method, which supported to form high-quality hetero-interface connection to efficiently improve the photocatalytic activity . Specially, 1D Zn 0.5 Cd 0.5 S (ZCS) nanorods and 2D WO 3 nanosheets were used to construct the S-scheme photocatalysts that have fully reflected both two components’ structural and morphological features. By DFT calculation, this S-scheme photogenerated electron transfer channel could be predicted by the work function between Zn 0.5 Cd 0.5 S (4.132 eV relative to vacuum level) and WO 3 (5.175 eV), thus the practical effect of the S-scheme heterojunction could support the electron flow from the valence band of Zn 0.5 Cd 0.5 S to the conduction band of WO 3 under the built-in electric field in the space charge region. Meanwhile, PL spectra and electrochemical measurement together reveal the photogenerated electron separation enhancement of ZCSW composites. For photocatalysis , ZCSW40 (40 stands for the weight ratio of WO 3 versus Zn 0.5 Cd 0.5 S) was the best catalyst among the as-prepared samples with the Cr (VI) degradation rate of 20.4 μmol min −1 ·g −1 cat. , which was nearly 3 times and 2 times higher than those of bare ZCS and the rest of ZCSW photocatalysts under the simulated solar-driven irradiation. Furthermore, ZCSW40 possessed excellent cycling stability in photocatalytic reaction, as well as the highest reaction dynamic constant of 0.92103.