In situ construction of Bi4O5I2-Bi2O2CO3-BiOCl0.8I0.2 n-p-n heterojunction for enhanced photocatalytic performance

In this work, Bi4O5I2-Bi2O2CO3-BiOCl0.8I0.2 n-p-n heterojunction was synthesized by in-situ growth method. Different types of BiOX (X = Br, Cl and I) materials were combined to optimize the charge separation of prepared heterogeneous junction so as to improve the photocatalytic performance. It had been proved by various characterization methods that the charge carrier recombination would be greatly suppressed under the action of internal electric field at the interface when n-p-n heterojunction was formed. Specially, 20-Bi4O5I2-Bi2O2CO3-BiOCl0.8I0.2 presented the best photocatalytic performance, which could degrade 99% of Rhodamine B (RhB) in 60 min under 500 W Xe lamp source. BiOCl0.8I0.2 improves the performance of photocatalytic and broaden the light absorption range of pure BiOI. This work provides a new perspective to design ternary structures that enhance photocatalytic performance.