Degradation of microcystin-LR by highly efficient AgBr/Ag3PO4/TiO2 heterojunction photocatalyst under simulated solar light irradiation

Abstract A novel photocatalyst AgBr/Ag 3 PO 4 /TiO 2 was developed by a simple facile in situ deposition method and used for degradation of mirocystin-LR. TiO 2 (P25) as a cost effective chemical was used to improve the stability of AgBr/Ag 3 PO 4 under simulated solar light irradiation. The photocatalytic activity tests for this heterojunction were conducted under simulated solar light irradiation using methyl orange as targeted pollutant. The results indicated that the optimal Ag to Ti molar ratio for the photocatalytic activity of the resulting heterojunction AgBr/Ag 3 PO 4 /TiO 2 was 1.5 (named as 1.5 BrPTi), which possessed higher photocatalytic capacity than AgBr/Ag 3 PO 4 . The 1.5 BrPTi heterojunction was also more stable than AgBr/Ag 3 PO 4 in photocatalysis. This highly efficient and relatively stable photocatalyst was further tested for degradation of the hepatotoxin microcystin-LR (MC-LR). The results suggested that MC-LR was much more easily degraded by 1.5 BrPTi than by AgBr/Ag 3 PO 4 . The quenching effects of different scavengers proved that reactive h + and •OH played important roles for MC-LR degradation.