Synthesis of CoWO/g-CN Z-scheme heterojunction for the efficient photodegradation of diazinon with the addition of HO.

Pesticides are on the list of substances that are routinely monitored by agencies and organizations in various natural environments and habitats. Diazinon (DZN) is the active ingredient in more than 20 agricultural pesticides, it causes the most damage and has been prohibited in many countries around the world. The final product CoWO/g-CN Z-scheme heterojunction was successfully synthesized in this work, where CoWO nanoparticles were deposited on the surface of g-CN. CoWO/g-CN structure allowed for the efficient separation of photo-generated electron-hole pairs, with electrons at the CoWO CB migrating to the g-CN VB and preserving the electrons at the g-CN CB and holes in the CoWO VB. The photodegradation efficiency of DZN using CoWO/g-CN Z-scheme heterojunction was investigated, as compared with its precursors, such as CoWO, and g-CN. CoWO/g-CN Z-scheme heterojunction demonstrated the highest degradation capacity for DZN removal. Based on the results, the photocatalysis of the CoWO4/g-C3N4 Z-scheme heterojunction can be recycled for the effective removal of DZN by simple washing after three runs, proving the heterojunction's stability and suggesting CoWO4 as a promising material for the removal of DZN from contaminated water sources.