Superior photocatalytic performance of a novel flower-like Bi24Si2O40-Bi2O2SiO3 composite via organic-guided crystal growth and bandgap regulation

Aurivillius oxide layered materials are formed by bismuth oxide and pseu-do-perovskite layers, which usually presents a mica-like lamellar structure, that is easy to stack with each other, affecting the exposure of active sites, thereby reducing its photocatalytic performance. Herein, the organic modifier is used to adjust the morphology to obtain Bi24Si2O40-Bi2O2SiO3 (BSO) with three-dimensional flower-like structure. Furthermore, the optimization of morphology promotes the effective formation of heterostructures, organic-mediated morphology growth and the regulation of heterojunction effectively improves the activity of superoxide radicals (•O2−) and holes (h+). Therefore, the organic-modified MBSO-2 shows excellent photocatalytic performance, and its degradation rates of rhodamine B (RhB), ciprofloxacin (CIP) and norfloxacin (NOR) can reach 98.7%, 87.4% and 89.0%, respectively. Moreover, the great improvement of the degradation of RhB and NOR by MBSO-2 can be attributed to the important role played by its active species (h+ and •O2−), which shows that it is more conducive to improving the degradation of pollutants with h+ and •O2− as the degradation path. The modification strategy of organic-mediated lamellar growth provides a new idea for the morphology control of layered metal oxide photocatalysts and broadens its application.