Analysis of the effect of visible photocatalytic reduction of Cr (VI) in industrial wastewater by hydrothermal synthesis of LaVO4/WO3 composite nanoplate
To solve the problem of high toxicity and strong migration of Cr (VI) in industrial wastewater, photocatalysts of LaVO4/WO3 composite nanoplate with different composite ratios were prepared by the hydrothermal method and characterized by XRD, SEM, XPS and DRS techniques. The results showed that LaVO4 could enter the lattice of WO3 , causing lattice defects. Lattice defects can be used as active sites to promote the separation of photogenic carriers and improve the photocatalytic activity of WO3. The Cr (VI) test in industrial wastewater for photocatalytic reduction under visible light showed that the photocatalytic reduction efficiency of LaVO4/WO3 composite nanoplate was higher than that of WO3. When LaVO4 loaded WO3 with a mass ratio of 3%, the photocatalytic reduction efficiency of the composite nanoplate was the highest, up to 92%, which was 8.3 times that of pure WO3. LaVO4 could diffuse the oxygen vacancy of WO3, improve the photogenerated electron migration rate at the interface, promote the photogenerated electron reduction Cr (VI), and improve the photocatalytic reduction of composite nanoplate. This study provides a theoretical reference for the research and development of efficient treatment technology of heavy metal industrial wastewater, especially refractory heavy metal pollutants.