Boosted photocatalytic efficiency of GQDs sensitized (BiO)2CO3/β-Bi2O3 heterojunction via enhanced interfacial charge transfer

Abstract

The NO gas is easily oxidized to form toxic by-products (NO2) during the oxidation process, which are adsorbed on the catalyst surface and inhibit the subsequent reaction. For photocatalytic NO removal, a significant challenge is to achieve catalytic stability while maintaining high conversion efficiency. Here, we fabricated a (BiO)2CO3/β-Bi2O3 heterostructure that enables efficient charge transfer and promotes the NO removal. We propose that the catalytic stability depends on the heterojunction structure, which is able to generate interfacial charge transfer channels. In addition, we further introduce graphene quantum dots on the heterojunction structure, which further strengthens the interfacial charge transfer dynamics and finally realizes that the NO2 byproduct could gain electrons and convert to the final product (nitrite or nitrate). This composite structure not only exhibits high activity for NO removal but also maintains long-term stability under visible light.