The advanced photocatalytic degradation of atrazine by direct Z-scheme Cu doped ZnO/g-C3N4

Herein, Cu was incorporated into ZnO lattice to reduce its band gap as well as to extend its visible radiation response. The obtained Cu-ZnO was continuously integrated with g-C₃N₄ to create Cu-ZnO/g-C₃N₄ Z-direct scheme photocatalyst for advanced atrazine removal. Radical scavenging experiments have been also conducted to clearly figure out photocatalytic mechanism for degradation of atrazine by the synthesized photocatalyst. The synthesized Cu-ZnO only utilized the generated h⁺ for atrazine degradation (direct and indirect via formation hydroxyl radicals (^• OH)) and the g-C₃N₄ only utilized the generated e⁻ for atrazine degradation (indirect via reaction with O₂ to form superoxide anion, which needed to continuously react with H₂O to form ^• OH). Therefore, the photocatalytic atrazine degradation by synthesized Cu-ZnO material was greater than that by synthesized g-C₃N₄ material. Cu-ZnO/g-C₃N₄ utilized both generated e⁻ and h⁺ for degradation of atrazine. Thus, the photocatalytic atrazine degradation by the synthesized Cu-ZnO/g-C₃N₄ was greater than those of single g-C₃N₄ or Cu-ZnO materials. Finally, the conducted recycling experiments indicated great stability of synthesized Cu-ZnO/g-C₃N₄ during long-term atrazine degradation process opening new era for application of the material in practical systems.