Abstract
In view of the environmental pollution caused by antibiotics, the creation of an efficient photocatalytic material is an effectual way to carry out water remediation. Herein, we developed a smart strategy to synthesize ZnO/Cu2O/g-C3N4 heterojunction photocatalysts for the photodegradation of hazardous antibiotics by one-pot synthesis method. In this system, the Cu2O nanoparticles with electrons reducing capacity were coupled with g-C3N4 composites. The photocarriers were generated from the electric field of type Ⅰ heterojunction between ZnO and g-C3N4 and type Ⅱ heterojunction between Cu2O and g-C3N4. ZnO as a co-catalyst was doped to Cu2O/g-C3N4 catalyst system for removal of broad-spectrum antibiotics with the condition of visible light to protect Cu2O from photocorrosion, which thereby accelerated photocatalytic reactivity. Benefiting by new p-n-n heterojunction, the resulting ZnO/Cu2O/g-C3N4 composites had an excellent degradation performance of broad-spectrum antibiotics such as tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC) and ciprofloxacin (CIP), the degradation of which were 98.79%, 99.5%, 95.35% and 73.53%. In particular, ZnO/Cu2O/g-C3N4 photocatalysts showed a very high degradation rate of 98.79% for TC in first 30 min under visible light, which was 1.35 and 10.62 times higher than that of Cu2O/g-C3N4 and g-C3N4, respectively. This work gives a fresh visual aspect for simultaneously solving the instability deficiencies of traditional photocatalysts and improving photocatalytic performance.