Self-assembled graphitic carbon nitride regulated by carbon quantum dots with optimized electronic band structure for enhanced photocatalytic degradation of diclofenac

Diclofenac (DCF) has received widespread attention due to its potential negative influence on the environment and human health. And the development of efficient technology for DCF removal becomes a global challenge. Herein, a novel visible-light-driven photocatalyst (PCN@(m)CQDs-2) was successfully synthesized using self-assembly melamine-cyanuric acid supermolecules regulated by (m)CQDs as precursors. (m)CQDs could involve in the process of supramolecular self-assembly through hydrogen bonding and show regulation effects on the microstructure control, band structure adjustment, and performance promotion of as-prepared PCN@(m)CQDs-2. Benefited from the multiple advantages, PCN@(m)CQDs-2 exhibited about 25 times higher degradation rate to-wards DCF than pure graphitic carbon nitride. Experimental results reflected that photogenerated holes dominated the degradation of DCF, while hydroxyl radical showed a negligible contribution. Further research indicated that PCN@(m)CQDs-2 has high toxicity reduction properties, mineralization ability, and reusability. Our findings provide a novel idea for the fabrication of enhanced g-C3N4 for environmental protection.

Automated summary

In this study, a novel visible-light-driven photocatalyst (PCN@(m)CQDs-2) was successfully synthesized, which exhibited significantly improved degradation rate towards diclofenac (DCF) through regulating the supramolecular self-assembly process, microstructure, and band energy levels. Experimental results indicated that photogenerated holes played a dominant role in DCF degradation, while the contribution of hydroxyl radicals was negligible. Moreover, PCN@(m)CQDs-2 showed high toxicity reduction properties, mineralization ability, and reusability.