Construction of p-n type Bi_2O_3/Bi_4NbO_8Cl 0D/2D heterojunction with enhanced photodegradation performance for organic pollutants

摘要

Bi4NbO8Cl is a novel bismuth-based catalyst with a 2D sheet structure for photodegradation under visible light irradiation. However, Bi4NbO8Cl semiconductor has low quantum efficiency, as well as the photogenerated electrons (e(-)) and holes (h(+)) tend to recombine in a single semiconductor, thereby decreasing their degradation efficiency. Hence, in this work, Bi2O3/Bi4NbO8Cl 0D/2D heterojunctions containing Bi2O3 quantum dots were prepared to enhance the photocatalytic performance, in which e(-) and h(+) were separated and transferred to different semiconductors for oxidation and reduction, respectively. Compared to bare Bi4NbO8Cl, the photocatalytic activity of 0.5 Bi2O3/Bi4NbO8Cl increases by 2.6 times in the degradation of Rhodamine B since the formation of heterojunctions. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) has confirmed the formation of heterojunction. The photoluminescence (PL), photocurrent, and electrochemical impedance spectra (EIS) tests indicate that the quantum efficiency has been improved. This research may be valuable for the industrial application of photocatalysts and provide a new idea for designing photocatalysts.