Pure BiVO4 and three TiO2/BiVO4 composite photocatalysts with Bi^3+: Ti^{4+} molar ratios of 1: 1, 2: 1, and 4: 1 were readily synthesized for the first time using a one-pot hydrothermal procedure for the photodegradation of ciprofloxacin. Conducting the hydrothermal reaction in a basic medium yielded single-phase scheelite monoclinic polymorphic BiVO4 (ms- BiVO4) in the composite samples. Microstructural analysis showed spherical TiO2 nanoparticles with an average grain size of 120 nm embedded on the surface of BiVO4 nanoplates. The optimized composite exhibited a ciprofloxacin photodegradation reaction rate constant was about 3. 8 times higher than that of the pure BiVO4 sample. This significant enhancement is attributed to the formation of a TiO2/BiVO4 heterojunction, which promotes efficient charge separation. This research expands the knowledge on designing of BiVO4 -rich composites (with Bi^3+: Ti^{4+} molar ratio 1: 1) via heterogeneous junction engineering to enhance photocatalytic activity beyond that of pure BiVO4. This research also provided a perspective on using the BiVO4 -rich composites as effective photocatalysts as degradation of antibiotics in aqueous media under visible-light irradiation.
Dang et al. (Thu,) studied this question.