Efficient photo-switchable activation of periodate by nitrogen-vacancy-rich carbon nitride for organic contaminant removal: Theoretical predictions and experimental validations

This study presents a simple N2 calcination method at various temperatures to achieve nitrogen-vacancy-rich g-C3N4 for periodate (IO4-) activation under visible light. The developed system demonstrated remarkable effectiveness in eliminating various organic pollutants. Especially, bisphenol A, the model pollutant, could be completely removed within 30 min, exhibiting an activity 9.37 times higher than that of the background activator. Theoretical calculations suggest that small active molecules, including contaminants and oxidants, showed a higher affinity for adsorption onto the g-C3N4 surface in the presence of nitrogen vacancies. This promoted sufficient electron supply and rapid electron transfer, enhancing IO4- activation during decontamination. Furthermore, we comprehensively examined the evolution of reactive species, such as IO3•, •O2-, 1O2, •OH, and h+, and explored the application potential of the catalytic system. This work provides new insights into the design of photo-self-cleaning IO4- activators and highlights this method's potential for application in other oxidation systems.