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

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.