Novel metal-free in-plane functionalized graphitic carbon nitride with graphene quantum dots for effective photodegradation of 4-bromophenol

Abstract

The current study reveals the in-plane induction of graphene quantum dots (GQDs) into exfoliated graphitic carbon nitride to generate greener material for visible light driven photodegradation of 4–bromophenol, a novel brominated flame retardant. The physical and electrochemical analysis shows the GQDs induction within the exfoliated carbon nitride (CN-Ex), generating new impurities, thus exploiting higher visible–light. The CN-Ex has exceptional conductivity to convert electrons from valence band, while GQDs generate an electron field to enhance the catalytic activity on conduction band. Metal-free CN@GQD composite has shown efficient and consistent photodegradation rate of 4-BP under visible light, which could be debrominated and oxidized separately on conduction and valence band, respectively. EPR spectra reveals that 1O2 radicals prominently dominates the photodegradation of 4-BP. TOC removal and the rate kinetics of 4-BP was insignificantly reduced after consecutive 5-repeated cycles. Moreover, excellent stability and durability was observed under various reaction conditions to confirm the feasibility and broader applicability of the material in the industries. This research reveals the inclusion of GQDs within CN layers could modify the band structure, enhance hydrophilicity and photocatalytic efficacy, unveiling an ingenuity to architect an effective and visible-light driven metal-free photocatalyst for persistent NBFRs degradation.