Facile synthesis of ZnO/GO/Ag3PO4 heterojunction photocatalyst with excellent photodegradation activity for tetracycline hydrochloride under visible light

A novel ZnO/GO/Ag3PO4 heterojunction photocatalyst was synthesized by a facile ultrasonic-assisted precipitation method for wastewater treatment. The structure, morphology, optical properties and photoelectrochemical properties of the catalysts were tested by various characterization methods. Compared with pure Ag3PO4, all the composite catalysts show significantly enhanced photocatalytic activity for the degradation of tetracycline hydrochloride (TC). And ZnO (20 wt%)/GO (2 wt%)/Ag3PO4 catalyst displays the highest photo-degradation activity for TC (30 mg/L) without adjusting pH under visible light, while the degradation rate reaches 96.32 % adding 1.0 g/L catalyst. The enhanced photocatalytic activity can be attributed to the better adsorption ability, effective separation of photogenerated electron-hole pairs, the faster electron transmission and increased amount of active species. Besides, the composite has better cycling stability than Ag3PO4 which still has a relatively high photocatalytic activity after three uses. In addition, a possible mechanism is proposed through these experimental results at the end. Based on our research, this novel material has a good application prospect.