2D/2D layered BiOIO3/g-C3N4 S-scheme heterojunction for photocatalytic NO oxidation

Abstract

It is essential to promote interfacial separation and charge migration in heterojunctions for effectively driving surface photocatalytic reactions. In this work, we report the construction of a 2D/2D layered BiOIO3/g-C3N4 (BIO/CN) heterojunction for photocatalytic NO removal. The BIO/CN heterojunction exhibits a remarkably higher NO photo-oxidation removal rate (46.9%) compared to pristine BIO (20.1%) and CN (25.9%) under visible-light irradiation. Additionally, it effectively suppresses the formation of toxic NO2 intermediates during photocatalytic reaction. The improved photocatalytic performance of BIO/CN composite is caused by its S-scheme charge carrier transport mechanism, which is supported by Density Functional Theory simulations of work function and electron density difference, along with in-situ irradiated X-ray Photoelectron Spectroscopy and Electron Paramagnetic Resonance analyses. This S-scheme structure improves the interfacial carrier separation efficiency and retains the strong photo-redox ability. Our study demonstrates that construction of a S-scheme heterojunction is significant in the design and preparation of highly efficient photocatalysts for air purification.