Investigation of an enhanced Z-scheme magnetic recyclable BiVO4/GO/CoFe2O4 photocatalyst with visible-light-driven for highly efficient degradation of antibiotics

The BiVO4/GO/CoFe2O4 composite photocatalyst with a good visible light response was successfully synthesized by the liquid-phase precipitation mechanical mixing method. The structure, composition, morphology and optical properties were investigated. Compared with pure BiVO4 and BiVO4/GO, the BiVO4/GO/CoFe2O4 composite photocatalyst has a better degradation effect, when exposed to visible light for 40 ​min (the photocatalyst dosage is 1.00 ​g/L), the degradation rate of tetracycline hydrochloride (TC) can reach 90.14%. Under the optimal reaction conditions, it also shows a good degradation ability to several other antibiotics. After repeated use three times, it still has a good degradation effect, indicating that it has good stability. The addition of GO has promoted the separation of electrons and holes, effectively prevented recombination of photogenerated electrons, made BiVO4 and CoFe2O4 tightly connected, and a strong interfacial interaction occurs between the various substances. The addition of CoFe2O4 solved the problem that BiVO4 is difficult to recycle and increased the specific surface area of the photocatalyst. The photocatalytic activity of BiVO4/GO/CoFe2O4 composite photocatalyst has been improved obviously, which is attributed to the construction of Z-scheme heterojunction. Besides, the free radical capture experiment shows that •O2− is the main active substance in the reaction process, and h+ plays a supporting role. This study provides a feasible method for degrading antibiotics.