A novel Z-scheme CdS/Bi4O5Br2 heterostructure with mechanism analysis: Enhanced photocatalytic performance

The novel Z-scheme CdS/Bi4O5Br2 heterostructure was successfully synthesized by a simple mixed-solvent thermal method. It proved that the Z-scheme CdS/Bi4O5Br2 heterojunction was constructed by XRD, SEM, TEM and XPS. The synthesis of CdS nanospheres on ultra-thin Bi4O5Br2 nanosheets to form a heterojunction interface was beneficial to the dispersion and transfer of the photogenerated electron-hole pairs, which was demonstrated by PL, i-t and EIS. UV-Vis diffuse reflectance spectra attested CdS/Bi4O5Br2 heterojunction enhanced utilization of visible light. The Z-scheme 0.5-CdS/Bi4O5Br2 heterojunction exhibited the highest photocatalytic performance for degradation process of CIP and TC than that of pure CdS and Bi4O5Br2. In addition, recycling tests declared that the Z-scheme 0.5-CdS/Bi4O5Br2 heterojunction compared with single CdS had higher stability and durability, attributing to effectively alleviating photocorrosion of CdS. It could be seen from the trapping agent experiment that superoxide free radicals and hydroxyl free radicals were the main active substances. The possible photocatalytic mechanism of the Z-scheme 0.5-CdS/Bi4O5Br2 heterojunction under visible light irradiation was proposed. (C) 2020 Elsevier B.V. All rights reserved.