Rational design of α-Fe₂O₃ nanocubes supported BiVO₄ Z-scheme photocatalyst for photocatalytic degradation of antibiotic under visible light

The Z-scheme BiVO₄/α-Fe₂O₃ photocatalyst was synthesized by a simple hydrothermal method. The photocatalyst is composed of α-Fe₂O₃ nanocubes with a regular cubic structure and the BiVO₄ particles distributed on the surface of the α-Fe₂O₃ nanocubes. The photocatalytic performance of Z-scheme BiVO₄/α-Fe₂O₃ photocatalyst was investigated in terms of its capacity for photodegradation of tetracycline hydrochloride. Improved photocatalytic activity was observed for Z-scheme BiVO₄/α-Fe₂O₃ photocatalyst compared with pure BiVO₄ and α-Fe₂O₃ nanocubes under visible light irradiation. Studies of its morphology, physicochemical properties and photoelectrochemical behaviors demonstrated that BiVO₄ loading on the surface of α-Fe₂O₃ nanocubes forms a Z-scheme heterojunction, which increases the specific surface area and significantly promotes the separation of photoinduced carriers. The main active species were determined to be OH and h⁺ by ESR technique and trapping experiments. We propose a possible photocatalytic mechanism of Z-scheme BiVO₄/α-Fe₂O₃ photocatalyst system. This study may also provide a novel and eco-friendly demonstration of a useful strategy for the design and preparation of special structure photocatalytic materials.