Composite soft template-assisted construction of a flower-like β-Bi2O3/Bi2O2CO3 heterojunction photocatalyst for the enhanced simulated sunlight photocatalytic degradation of tetracycline

Abstract A three-dimensional (3D) flower-like β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunction photocatalyst was synthesized via decomposition of the precursor fabricated using a composite soft template, which was constructed from dl -aspartic acid and nonionic amphiphilic triblock copolymer (Pluronic F127). The morphology, phase structure, composition, effect of reactant concentration, and possible formation mechanism were systematically studied. The results showed that dl -aspartic acid was chosen as the coordination- and structure-directing agent, while F127 was used as the capping agent during preparation of the precursor. The as-prepared flower-like β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunction obtained after calcination of the self-sacrificing precursor at 290 °C showed excellent photocatalytic performance in the degradation of the refractory colorless antibiotic agent tetracycline (TC) under simulated sunlight irradiation, with 98.79% TC degradation being achieved within 60 min of irradiation. This excellent photocatalytic performance was attributed to the narrow band gap, heterojunction structure, and 3D hierarchical structure. The results further revealed that photogenerated holes (h + ) and hydroxyl radicals ( • OH) dominated the photocatalytic process. Furthermore, the β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunction catalyst was not photocorroded after six consecutive cycles, suggesting an excellent photostability.