A novel Z-scheme AgBr/P-g-C3N4 heterojunction photocatalyst: Excellent photocatalytic performance and photocatalytic mechanism for ephedrine degradation

A series of AgBr/P-g-C3N4 (AB/CN) were fabricated via in-situ growth of AgBr particles on the surface of calcined P-g-C3N4 layered mesoporous materials, and the catalysts were used for the photocatalytic degradation of ephedrine (EHP) under simulated solar irradiation. All photocatalysts demonstrated high photocatalytic performances for EPH degradation, and the AB/CN (5:1) showed the best photocatalytic activity. The holes, superoxide radicals and singlet oxygen were the dominant reactive oxygen species involved in EPH degradation. The enhanced photocatalytic performance of AgBr/P-g-C3N4 was ascribed to the formation of Ag nanoparticles and the Z-scheme mechanism. EPH degradation was accelerated by dissolved organic matter or HCO3− at low concentrations, but inhibited at high levels. The addition of CO32- enhanced EPH degradation, and NO3− suppressed the degradation. AB/CN was also able to degrade EPH in surface water and secondary effluent, implying the potential of the prepared materials in illicit drugs removal in practical applications.