S‑Scheme Nanometer-Sized Bi₃NbO₇/Bi₂O₂CO₃ Heterojunction\nPhotocatalysts for Efficient Pollutant Degradation

Abstract

Bi₃NbO₇(abbreviated\nBNO) exhibits favorable\nvisible light responsiveness and chemical stability as a photocatalyst,\nwhich could be utilized for the purification of aqueous environments.\nHowever, the high photogenerated carrier complexation rate severely\nrestricts the photocatalytic reaction. In this work, the one-pot solvent\nmethod was used to improve the photocatalytic ability by preparing\nS-scheme heterojunction composite photocatalysts by adding urea. The\ncharacteristic lamellar structure of Bi₂O₂CO₃(abbreviated BOC) can increase the specific surface area and\nprovide more active sites for the photoreaction. The construction\nof the S-scheme heterojunction could promote effective charge transfer\nand consume the unnecessary electrons and holes; meanwhile, the whole\nsystem is maintained at a high redox level so as to oxidize and decompose\nthe pollutants. The experimental results showed that nanometer-sized\n1.2 Bi₃NbO₇/Bi₂O₂CO₃(abbreviated 1.2BNO/BOC) possesses good degradation effects\nfor the simulated pollutants, the degradation efficiency is significantly\nimproved compared with pure BNO, and the photocatalyst exhibits good\ncyclic stability.