Electron beam irradiation treatment of Ag/Bi2WO6/CdWO4 heterogeneous material with enhanced photocatalytic activity

An efficient ternary Ag/Bi2WO6/CdWO4 heterostructure material was prepared through a facile hydrothermal route. The in-situ loading precisely regulated the distribution of silver nanoparticles on the heterojunction surface. Besides, electron beam irradiation was used for artificially creating interface defects to the material. Under visible light irradiation, the degradation efficiency of the heterostructure material was improved obviously. Within 20 min, the removal efficiency of the treated material for carmine could reach about 100% (50 mL, 50 mg/L), while, that for hexavalent chromium (Cr6+) could reach about 100% (50 mL, 10 mg/L) within 90 min. In addition, the results showed that, 4% Ag load rate had the best improvement on the photocatalytic performance of the ternary heterostructure material. Proper amount of supported in-situ nano-silver induced the resonance of the plasma on the catalytic interface and synergized with Bi3+ to improve the catalytic efficiency. PL, DRS and XPS results proved that ternary heterostructure could effectively inhibit the rapid recombination of electron hole pairs of Ag/Bi2WO6/CdWO4. As for the role of electron beam irradiation, it could improve the content of free hydroxyl groups on the material surface and enhance catalytic capacity of the heterogeneous material. A feasible reaction pathway and photocatalytic mechanism for the degradation of carmine was investigated by GC-MS, and the main role of •OH in the catalytic process was obtained by using different scavengers.