In-situ one-step synthesis of porous monolayer carbon nitride nanosheets doped with carbon quantum dots for photocatalytic degradation of Meloxicam

The energy storage and upconversion effect of carbon quantum dots (CQDs) could improve the photocatalytic efficiency of materials. In this study, a visible-light-driven photocatalyst, CQDs-doped carbon nitride nanosheets composite (CNS/CQDs) was in-situ synthesized by the thermal stripping of carbon nitride bulk (CNB). The as-prepared CNS/CQDs photocatalyst was systematically characterized and applied to the removal of Meloxicam (Mel) in water. The results showed that the introduction of CQDs could improve the visible light utilization of the carbon nitride. Mel (50 mL, 10 mg L−1) was degraded by 99.60% in 45 min with CNS/CQDs (20 mg). The stability and recycling experiments showed that CNS/CQDs could maintain high photocatalytic activity under complex matrix and multiple cycles. This work will provide a new attempt to synthesize the CQDs doped photocatalytic materials for the effective removal of organic pollutants in water under visible light. [Display omitted] •CNS/CQDs were first prepared by in-situ one-step method.•The effects of thermal stripping conditions on the formation of CQDs were studied.•The mechanism that CQDs enhance the sunlight utilization rate of CNS/CQDs is revealed.•Mel was efficiently degraded by CNS/CQDs and the removal rate was 99.60%.•CNS/CQDs have strong anti-interference ability to water quality and excellent recyclability.