Large-Scale Synthesis of p-n Heterojunction Bi2O3/TiO2 Nanostructures as Photocatalysts for Removal of Antibiotics under Visible Light

Although photocatalysis has been proved to be a promising technology in solving various environmental problems, the preparation of visible light-driven photocatalysts on a large scale in a simple and sustainable manner still remains a technical challenge. Here, we demonstrate a simple one-pot method for the large-scale synthesis of a novel Bi2O3/TiO2 visible light-driven photocatalyst by coupling low-cost TiO2 with strong visible-light absorption of Bi2O3. The as-synthesized Bi2O3/TiO2 photocatalyst exhibits efficient charge separation due to the formation of a p-n heterojunction. Additionally, the porous nanostructure of Bi2O3/TiO2 provides high surface area and abundant active sites, realizing the complete degradation (100%) of tetracyclines under visible light (lambda > 420 nm), which successfully breaks through the bottleneck of incomplete degradation of tetracyclines under visible light irradiation for most of the reported photocatalysts. Notably, since our method is based on the one-pot synthesis without any pretreatment procedure for the precursors of Bi2O3 and TiO2, it is very suitable for the development of large-scale synthesis by using a big reactor, producing up to 23.9 g of Bi2O3/TiO2 nanocatalyst in a single synthesis, which indicates its considerable potential for further scale-up production. Therefore, this study opens a new window for the large-scale synthesis of other visible light-driven photocatalysts with excellent photocatalytic performances.

Automated summary

The study demonstrates a simple one-pot method for the large-scale synthesis of Bi2O3/TiO2 visible light-driven photocatalyst, allowing complete degradation of tetracyclines under visible light due to efficient charge separation and porous nanostructure. This method shows considerable potential for further scale-up production of photocatalysts with excellent performance under visible light.