Facile synthesis of magnetically retrievable Fe3O4/BiVO4/CdS heterojunction composite for enhanced photocatalytic degradation of tetracycline under visible light

Abstract

• A novel Fe 3 O 4 /BiVO 4 /CdS heterostructured composite was prepared for the first time. • The composite promoted interfacial charge transfer and extended the visible light response. • The Fe 3 O 4 /BiVO 4 /CdS catalyst exhibited excellent performance for TC photodegradation. • Fe 3 O 4 /BiVO 4 /CdS exhibited good universal applicability, stability and reusability. • A possible photocatalytic mechanism of TC over Fe 3 O 4 /BiVO 4 /CdS was proposed. Nowadays, designing photocatalysts with high activity and recyclability for the degradation of pollutants is still a challenging problem. In this paper, a novel Fe 3 O 4 /BiVO 4 /CdS (FBC) heterojunction photocatalyst was firstly fabricated by simultaneously decorating CdS on the surface of pristine Fe 3 O 4 and BiVO 4 in a low-temperature water bath system. The FBC photocatalyst can enhance the absorption range of visible light and facilitate the separation and transfer of charges. Simultaneously, it can also provide large specific surface area and excellent magnetic response. FBC-3 displayed the highest degradation rate of tetracycline (87.37%) under visible light irradiation. Moreover, the important parameters affecting the photocatalytic activity were investigated to simulate the degradation of TC in real aqueous system. More importantly, the synthesized magnetic photocatalyst exhibited good universal applicability, stability and reusability. The Z-scheme transfer pathway for improving photocatalytic performance was also proposed based on the results of radical trapping experiments, electron spin resonance (ESR) measurement, optical and photoelectrochemical analysis.