Synthesis of Cu3P/SnO2composites for degradation of tetracycline hydrochloride in wastewater

Abstract

Antibiotic drugs have become dominating organic pollutants in water resources, and efficient removal of antibiotic drugs is the priority task to protect the water environment. Cu3P/SnO2 photocatalysts of various Cu3P loadings (10-40 wt% Cu3P) were synthesized using a combination of hydrothermal synthesis and a partial annealing method. Their photocatalytic activity was tested for tetracycline hydrochloride (TC-HCl) degradation under visible light irradiation. Cu3P/SnO2 samples were characterized by X-ray diffraction (XRD), N2-adsorption, ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The results showed that the p-n type heterostructure between Cu3P and SnO2 was successfully constructed, and addition of Cu3P to SnO2 could improve its photocatalytic activity at an optimized loading of 30 wt% Cu3P. In photocatalytic degradation studies, removal rates of around 80% were found in 30 minutes of dark reaction and 140 min of photodegradation. The removal rate was superior to that of Cu3P and SnO2 alone under the same experimental conditions. According to trapping experiments and electron spin resonance (ESR) measurements, photogenerated holes (h+) and superoxide radicals O2- were considered as the main oxidation species in the present system. Finally, the reuse experiments showed high stability of Cu3P/SnO2. This study reports Cu3P as a cocatalyst combined with semiconductor SnO2 to form a highly efficient heterogeneous photocatalyst for the degradation of tetracycline hydrochloride for the first time. This journal is