A comparison study of the photocatalytic mechanism and performance of Bi2S3-based binary composite (Cu2O/Bi2S3) and ternary composite (NH2-UiO-66/BiOBr/Bi2S3) photocatalyst for tetracycline degradation under visible-light irradiation

To study the degradation of tetracycline by Bi2S3-based binary composite and ternary photocatalysts, Cu2O/Bi2S3 NH2-UiO-66/BiOBr/Bi2S3 was successfully fabricated solvothermal method, which can effectively stably degrade (TC). The crystal structure, chemical composition, microscopic morphology as-prepared sample were analysed X-ray diffraction (XRD) scanning electron microscopy (SEM). photocatalytic performance photocatalyst estimated TC under visible-light irradiation. results showed that removal ratio are 95.2% 93.2%, respectively. photoelectric properties material evaluated PL EIS analysis, compared to Bi2S3, overall visible light absorption capacity, as well separation transfer rates photogenerated carriers composites have been significantly improved. Both achieve a good photodegradation for TC, but UV–vis DRS spectrum, Mott–Schottky curve, free radical trapping experiments show their mechanism is different. For Cu2O/Bi2S3, •O2− h+ main active species in reaction process, among plays most important role, •OH has almost no effect, NH2-UiO-66/BiOBr/Bi2S3, h+. possible mechanisms Z-scheme double Z-schemes proposed,