Thin-walled vesicular Triazole-CN-PDI with electronic n→π* excitation and directional movement for enhanced atrazine photodegradation

Polymeric carbon nitride (PCN) as a competitive non-metal photocatalyst, has been widely applied in water treatment. However, the limited visible-light utilization and high photocarrier recombination rate restrict its photocatalytic efficiency. Herein, triazole and pyromellitic diimide were applied for the bimolecular decoration of polymeric carbon nitride (PCN) to fabricate TA-CN-PDI for the photodegradation of atrazine. The thin-walled vesicular morphology in TA-CN-PDI can enhance the n→π* electron excitation, and the donor-π-acceptor electronic structure can promote the directional movement of photogenerated electrons and holes. The theoretical and experimental results suggested that the vesicular structure and the donor-π-acceptor electronic structure synergistically promoted the photoactivity of the catalyst. Compared to the pristine PCN, the reaction rate constants of atrazine by TA-CN-PDI increased to 6.64-fold, achieving a 95 % removal rate. It was found that1O2, OH, h+, ·O2- were contributed to the ATZ degradation. In addition, mainly 14 intermediates and two pathways were proposed according to the LC-MS analysis. Hopefully, this modification strategy of PCN and its application in ATZ degradation can pave a way for subsequent research on the modification of photocatalysts.