TiO2/Fe2O3/Bi2WO6 Heterojunction with Excellent Carrier Separation Efficiency for Efficient Degradation of Rhodamine B

Abstract

Due to the fast-paced growth of industries, the release of substantial amounts of industrial wastewater, especially organic contaminants like dyes, presents a serious risk to both human health and the environment. However, achieving fast and efficient treatment for wastewater containing organic dyes in an energy-saving manner remains a challenge due to complicated processes and high costs in treatment. Herein, a novel ternary heterojunction (TiO₂/Fe₂O₃/Bi₂WO₆) by TiO₂ and Fe₂O₃ nanoparticles well-dispersed on Bi₂WO₆ nanosheets was proposed to ingeniously address these challenges. Under visible light, our TiO₂/Fe₂O₃/Bi₂WO₆ composite exhibits fast and efficient degradation for the representative dye Rhodamine B, achieving a 98.95% degradation rate in a short time, significantly outperforming individual and binary composites. Ultraviolet–visible and photoluminescence spectroscopy demonstrated the composite’s enhanced visible light absorption and efficient carrier separation. More importantly, the ternary photocatalyst showed excellent stability and reusability, maintaining high performance over multiple cycles. Active species capture identified holes and superoxide radicals as key contributors to the degradation process. This research offers a potential solution for addressing organic dye wastewater by utilizing the improved photocatalytic efficiency of the TiO₂/Fe₂O₃/Bi₂WO₆ heterojunction.