A novel double S-scheme photocatalyst Bi7O9I3/Cd0.5Zn0.5S QDs/WO3-x with efficient full-spectrum-induced phenol photodegradation

In this work, Bi7O9I3/Cd0.5Zn0.5S QDs/WO3-x ternary heterojunction with full spectrum response was prepared and applied in the photodegradation of phenol. The results of photocatalytic experiments showed that the prepared Bi7O9I3/Cd0.5Zn0.5S QDs/WO3-x heterojunction had the highest performance under full spectrum, visible and near-infrared light irradiation, and the reaction rates were 4.02, 3.75 and 5.71 times that of pure Bi7O9I3, respectively. This performance improvement results from the construction of double S-scheme hetemjunction and the full-spectrum response, which had effective charge distribution and migration as well as an excellent response to sunlight. In addition,center dot OH and center dot O-2(-) took the lead role in the process of photodegradation. Combined with the free radical-trapping experiment, ESR experiment and DFT theoretical calculation, the photocatalytic mechanism of double S-scheme system was proposed. This work is contributory to designing novel photocatalytic materials with dual S-scheme heterojunction and the efficient purification of wastewater in environmental remediation.

Automated summary

A Bi7O9I3/Cd0.5Zn0.5S QDs/WO3-x ternary heterojunction with full spectrum response was prepared and applied in the photodegradation of phenol. The heterojunction showed the highest performance under full spectrum, visible, and near-infrared light irradiation, with reaction rates 4.02, 3.75, and 5.71 times higher than pure Bi7O9I3, respectively. This improvement is attributed to the construction of a double S-scheme heterojunction and full-spectrum response, allowing for effective charge distribution and migration as well as excellent response to sunlight.