Font Size: a A A

Synthesis And Photocatalytic Performance Of Bismuth Sulfide/Bismuth Oxide Based Semiconductor Composites

Posted on:2016-10-25Degree:MasterType:Thesis
Country:ChinaCandidate:Z M JiaFull Text:PDF
GTID:2191330461479342Subject:Materials science
Abstract/Summary:PDF Full Text Request
Photocatalytic technology is considered to be one of the effective means to solve environmental problems and it has a very broad application prospect. Currently, besides the elaborate modifications of the traditional TiO2 photocatalyst, many efforts have been made to explore novel and efficient photocatalytic materials. In recent years, more and more attention has been focused on bismuth oxide based semiconductor materials owing to their special layer structure, good stability and photocatalytic activity. However, pure bismuth oxide based photocatalysts have relatively low utilization rate of solar energy, which limit their application in photocatalysis significantly. So it’s essential to improve their photocatalytic efficiencies by certain modification. In this paper, a series of bismuth oxide based photocatalysts recombined with Bi2S3 were synthesized, and their photocatalytic properties were also studied. The main contents are discussed as follows:1. Novel Bi2S3/BiOCl photocatalysts were successfully prepared by a facile biomolecule-assisted hydrothermal method, and L-cysteine (L-Cys) was used as the sulfur source. The structures, compositions, morphology and optical properties of the synthesized samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy (DRS). The presence of Bi2S3 in the Bi2S3/BiOCl composites could not only improve the optical properties but also enhance the photocatalytic activities for the degradation of Rhodamine B (RhB) under visible-light irradiation (λ>420 nm). The enhanced photocatalytic activities could be ascribed to the effective separation of photoinduced electrons and holes and the photosensitization of dye.2. Bi2S3/BiOBr photocatalysts were synthesized via a hydrothermal process using Bi(NO3)3, KBr and L-Cys as starting materials. Modern characterization methods, such as XRD, XPS, TEM, HRTEM and DRS, were carried out to analyze the structures, morphology and optical properties of the samples. Obvious red shifts of absorption edges of the photocatalysts were observed, and the absorptivity of visible light was enhanced. Photocatalysts showed excellent photocatalytic activities over RhB.3. Under hydrothermal conditions, Bi2S3/Bi2O2CO3 photocatalysts were prepared with Bi(NO3)3、Na2CO3 and L-Cys as raw materials. XRD, XPS, SEM and HRTEM were used to analyze the crystal structures, composition and morphology of photocatalysts, and the optical properties were evaluated by DRS. The results suggested that the visible light absorption properties of samples were greatly enhanced with the introduction of Bi2S3, and the photocatalysts displayed high photocatalytic efficiencies under simulated sunlight and visible light (λ>400 nm) irradiation.
Keywords/Search Tags:Bismuth oxide based semiconductor, Bi2S3, Photocatalysis, L-cysteine, Biomolecule-assisted hydrothermal
PDF Full Text Request
Related items