Synergetic effect of Fe₂O₃ and BiVO₄ as photocatalyst nanocomposites for improved photo-Fenton catalytic activity

Photo-Fenton reactions and the related functional nanomaterials have been widely studied for applications in wastewater treatment industry. Herein, visible-light-responsive Fe₂O₃ nanoparticle-decorated BiVO₄ nanoplates were designed and successfully prepared through a one-pot hydrothermal route. The as-prepared Fe₂O₃/BiVO₄ nanocomposites exhibit excellent photo-Fenton catalytic activity toward the discoloration of methylene blue (MB) and Rhodamine B (RhB) dye molecules in the presence of H₂O₂. The experimental results indicate that nearly 100% of MB (100 mL, 10 mg L⁻¹) and RhB (100 mL, 5 mg L⁻¹) dye molecules are degraded in the presence of 1 g L⁻¹ Fe₂O₃/BiVO₄-1 (FB-1) photo-Fenton catalyst and 0.5 mL of H₂O₂ within 20 min. The Fe₂O₃/BiVO₄ Fenton photocatalyst also demonstrates high reusability under visible light irradiation with λ ≥ 420 nm. The photoinduced electrons on the conduction band of BiVO₄ nanoplates can move toward the surface of Fe₂O₃/BiVO₄ to accelerate the reduction of Fe³⁺; then, the as-formed Fe²⁺ ions on the surface of the catalyst greatly enhance the decomposition of H₂O₂ to form reactive ^·OH species for the use in photodegradation of MB and RhB dye molecules. The synergetic effect of Fe₂O₃ and BiVO₄ reported in this work might provide more opportunity to fabricate other novel semiconductor-based Fenton nanocomposites for contamination treatments in wastewater.