Externally modified Bi12SiO20 with BiOI: n-p heterojunctions for effectually photocatalytic degradation of bisphenol A

The effectual removal of bisphenol A (BPA) molecules is of great significance considering the hazards to the environment and human health. For such, externally BiOI-decorated Bi12SiO20 (BSI) composites were successfully fabricated via a facile post-synthesis protocol and systematically characterized by various analytical techniques. Both expected components were identified and combined tightly in composites to generate n-p heterojunction structures. Under the visible light, these n-p heterojunction composites BSI provided the significantly improved photocatalytic removal abilities of colorless BPA. Particularly, the best candidate BSI-60 owned the largest apparent reaction rate constant (Kapp) 32.72 × 10−3 min−1 that were 48.8 and 2.04 times of those Bi12SiO20 and mixture BSI 60, mainly attributing to the enlarged specific surface area (SBET), strengthened visible light harvesting, and boosted charge carriers separation and further active species generation by heterojunction structures with the suitable phase composition. These composites possessed favorable reusability and structural stability and followed a typical type-II mechanism in the light of entrapping experimental and analytical results. This study may provide a research guidance for the creation of Bi12SiO20-based composites for effectual BPA removal through photocatalytic processes under visible light.