In-situ synthesis of Bi2S3 quantum dots for enhancing photodegradation of organic pollutants

Bismuth-based semiconductor materials have been considered as potential and green technology to alleviate various organic pollutants in recent years. In this work, we modified the Bi4NbO8Cl semiconductor via developing hetero-structure to overcome the shortcoming of fast recombination of electrons and holes. Bi2S3 quantum dots with Bi4NbO8Cl were successfully in-situ synthesized by the hydrothermal method, which were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy. The Bi2S3/Bi4NbO8Cl hetero-structure with broad light absorption region and low recombination efficiency was employed to photodegrade the organic pollutants (rhodamine B, Rh-B) under visible-light irradiation. It exhibited an enhanced photocatalytic degradation of Rh-B compared to Bi4NbO8Cl and Bi2S3, due to the in-situ synthesized Bi2S3 quantum dots that could effectively separate the photo-induced electron-hole pairs and suppress their recombination. Besides, the DFT data further explained the interfacial properties of Bi2S3/Bi4NbO8Cl. Thus, this work provides a unique idea in the design of novel photocatalysts, thereby promoting their potential application in industry.