Synthesis of In2O3/α-Bi2O3 heterojunction composites for photocatalytic degradation of tetracycline

To address the increasingly serious problem of antibiotic contamination, the hydrothermal method was employed to synthesize In 2 O 3 /α-Bi 2 O 3 photocatalysts. For tetracycline (TC) in aqueous solution, its photocatalytic degradation efficiency driven by visible light was systematically evaluated. The physical structure, optical properties and charge transfer of the composite materials were characterized and analyzed by XRD, PL and EIS. Nanoparticles In 2 O 3 was uniformly loaded on spindle-shaped α-Bi 2 O 3 , and the specific surface area increased to 17.08 m 2 /g. The composite material demonstrated a strong TC photodegradation ability, with a degradation efficiency of 86.99% (catalyst dosage = 30 mg, pH = 6, and initial TC concentration = 5 mg·L −1 ). The experimental results show that its excellent performance is attributed to the formation of heterojunctions, which have improved visible light absorption and efficient charge transfer. Free radical scavenger studies have confirmed that ·O₂ − and h + generated by photocatalysts account for the efficient degradation of TC, thus laying a foundation for the practical application of photocatalysts. This study innovatively constructs an In 2 O 3 /α-Bi 2 O 3 heterojunction with tailored loading ratio, which not only extends the visible-light response range but also promotes directional charge transfer, thus achieving superior photocatalytic degradation of tetracycline.