In Situ Fabrication of TiO2/(Bi2O3/Bi2O2.33) S-Scheme Heterojunction with Enhanced Bifunctional Photocatalysis for CO2 Reduction and Dye Removal

S-scheme heterojunctions enable efficient charge carrier separation while preserving strong redox ability, making them a research hotspot in photocatalysis. This work reports a simple and novel approach to prepare TiO2/(Bi2O3/Bi2O2.33) (TBBO) heterojunctions using Ti foil as precursors via a combined hydrothermal and calcination treatment. Photocatalytic tests demonstrate that the as-prepared TBBO catalysts exhibit significantly higher activity than pristine TiO2. TBBO-0.02 exhibits the best CO2 photoreduction performance and stability, achieving a CO generation rate of 152.5 μmol·g–1·h–1, due to its abundant oxygen vacancies and efficient S-scheme heterojunction interface. Furthermore, TBBO-0.02 also displays outstanding activity in the photodegradation of methylene blue (MB), with a degradation efficiency of 95% within 70 min. This work presents a new route for the green and facile preparation of highly efficient and stable S-scheme heterojunctions.