One-step synthesis of F-TiO2/g-C3N4heterojunction as highly efficient visible-light-active catalysts for tetrabromobisphenol A and sulfamethazine degradation

In order to achieve excellent visible light photoactivity of TiO2, it is still urgently required to extend their optical absorption ability and improve the potential of charge separation and migration. Here we synthesized highly efficient visible-light-active catalysts F-TiO2/g-C3N4 via a one-step-calcination method. Due to the synergic effect of ≡Ti−F, ≡Ti:F−H and the heterojunction, the obtained catalysts possess promising properties as highly efficient separation and migration of photoelectron-hole pairs. The prepared F-TiO2/g-C3N4 heterojunction can be successfully applied to degrade the widely used flame retardants and antibiotics. More than 95% of tetrabromobisphenol A (TBBPA) was decomposed after light illumination for 120 min, and 98% of sulfamethazine (SMZ) was degraded for 60 min by F-TiO2/g-C3N4. Furthermore, a reasonable catalytic mechanism for the F-TiO2/g-C3N4 catalysts was proposed. It could be seen that the active species •O2−, •OH, and h+ played important roles in the photocatalytic process under visible light illumination.