Photocatalysis coupling hydrogen peroxide synthesis and in-situ radical transform for tetracycline degradation

Although much effort has been put into hydrogen peroxide (H2O2) synthesis, multifunctional catalytic systems suitable for in-situ H2O2 utilization in the field have rarely been investigated. In this study, carbon nitride nanorod (GCN-Rod) is designed to couple H2O2 generating and activation for efficient environment remediation. The limitation of the sluggish hole oxidation kinetics during the photocatalytic H2O2 production is overcome by oxidation of electrostatically adsorbed contaminant molecules. Acid-activated carbon nitride nanomd binds a large number of protons onto the surface, forming an acidic micro-environment prone to protonating organic molecules into positively charged molecules and adsorbed on the negative zeta-potential catalyst surface for oxidation reactions. The in situ synthesized H2O2 is confirmed to be the origin of reactive oxygen species by EPR and band position analysis. The photocatalytic tetracycline (10 ppm) degradation ability approaches approximately 100 % within 10 min under visible-light irradiation. Cycle tests also demonstrated sufficient stability. This work achieves a delicate coupling of H2O2 production and in-situ utilization, which is sufficient for continuous pollutant degradation, expanding the catalyst design methods.