S-Scheme Nanometer-Sized Bi₃NbO₇/Bi₂O₂CO₃ Heterojunction Photocatalysts for Efficient Pollutant Degradation

Abstract

Bi3NbO7(abbreviated BNO) exhibits favorable visible light responsiveness and chemical stability as a photocatalyst, which could be utilized for the purification of aqueous environments. However, the high photogenerated carrier complexation rate severely restricts the photocatalytic reaction. In this work, the one-pot solvent method was used to improve the photocatalytic ability by preparing S-scheme heterojunction composite photocatalysts by adding urea. The characteristic lamellar structure of Bi2O2CO3(abbreviated BOC) can increase the specific surface area and provide more active sites for the photoreaction. The construction of the S-scheme heterojunction could promote effective charge transfer and consume the unnecessary electrons and holes; meanwhile, the whole system is maintained at a high redox level so as to oxidize and decompose the pollutants. The experimental results showed that nanometer-sized 1.2 Bi3NbO7/Bi2O2CO3(abbreviated 1.2BNO/BOC) possesses good degradation effects for the simulated pollutants, the degradation efficiency is significantly improved compared with pure BNO, and the photocatalyst exhibits good cyclic stability.