CsPbBr<sub>3</sub>-Modified Oxygen-Doped g-C<sub>3</sub>N<sub>4</sub> Heterojunctions for Sulfurization of Alkenes to Sulfoxides
Haibo Zhu, Yangbo Zhong, Honglei Zhang, Xinmei Xie, Bo Wang, Yang Liu, Qiangwen Fan, Zhanggao Le, Zongbo Xie
Abstract
Z -scheme heterostructures have become a novel class of photocatalysts that hold substantial significance in the domains of environmental and energy-related applications. This can be attributed to their distinctive charge separation and transfer pathways, which endow Z -scheme heterojunctions with robust redox capabilities. In this paper, we report a straightforward method for fabricating a perovskite-based Z -scheme heterojunction by integrating CsPbBr 3 nanocrystals with oxygen-doped g-C 3 N 4 (OCN). This heterojunction exhibited a high photocatalytic activity in the selective sulfoxidation reaction of alkenes with thiols. Under aerobic conditions, moderate to excellent yields of high-value sulfoxides with good functional compatibilities were achieved. This heterojunction showcases outstanding photocatalytic performance, remarkable stability, operational simplicity, high atom efficiency, and eco-friendly energy sources. The formation of Z -scheme heterojunction was corroborated by in situ X-ray photoelectron spectroscopy. These spectra revealed a negative shift in the binding energies of Cs 1s, Pb 4f, and Br 3d in CsPbBr 3, while a positive shift was observed for C 1s, N 1s, and O 1s in OCN upon light irradiation. This specific shift pattern effectively promotes the Z -scheme electron transfer from OCN to CsPbBr 3, which is conducive to the separation of electrons and holes, thereby enhancing the photoredox catalytic activity.