Direct Z-scheme Bi2O2CO3/porous g-C3N4 heterojunction for improved photocatalytic degradation performance

In this study, a series of direct Z-scheme bismuth subcarbonate (Bi2O2CO3)/porous graphitic carbon nitride (g-C3N4) composites was prepared by using a simple two-stage template free process. The structure, morphology, textural and optical properties were characterized by X-ray diffraction, N-2-physisorption, transmission electron microscopy, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, UV-vis analysis and photoluminescence spectroscopy. The catalytic properties of Bi2O2CO3/porous g-C3N4 composites were assessed using tetracycline hydrochloride under simulated solar light illumination. When the loading amount of Bi2O2CO3 was 2 wt%, the composite showed the highest catalytic activity, which was 5.1 times that of porous g-C3N4 nanosheets (PCNS). The enhanced photocatalytic properties of Bi2O2CO3/porous g-C3N4 may be attributed to the formation of heterojunction between Bi2O2CO3 and PCNS, resulting in the effective separation of photogenerated carriers and enhanced absorption of visible light. Furthermore, the novel photocatalyst had an excellent catalytic stability and could be recycled for five times without distinct loss of catalytic activity. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.