WO₃@Bi₂WO

Autor: Meifeng, Hao, Dejuan, Fa, Lihong, Qian, Yuqing, Miao
Rok vydání: 2018
Zdroj: Journal of nanoscience and nanotechnology. 18(7)
ISSN: 1533-4880
Popis: By hydrothermal reaction, the WO3@Bi2WO6/NiWO4 nanocomposite was prepared by the coprecipitation reaction between Bi3+/Ni2+ and WO2-4 in the presence of urea and PVP. It resulted in the formation of uniform and well-dispersed nanocomposite structures with ultrathin Bi2WO6/NiWO4 nanosheets attached with ultrafine WO3 nanoparticles. The nanocomposites exhibited a wide light absorbance up to 680 nm with low indirect band gaps of 2.54 eV, leading to outstanding photocatalytic efficiency for the degradation of both Rhodamine B (Rh B) and Xylenol Orange (XO) under visible light. With irradiation for only 15 minutes, Rh B was nearly completely degraded. XO, which is difficult to degrade usually, and the strong absorption peak nearly vanishes in about 60 min. The ultrathin Bi2WO6/NiWO4 nanosheets and ultrafine WO3 nanoparticles mean high specific areas and high active sites. A lot of hydroxy groups in WO3@Bi2WO6/NiWO4-III due to the presence of Ni and Bi helps for the formation of ˙OH. According to the ladder theory, the photogenerated e- and h+ by the irradiation light of high wavelength according with band gap can be activated again by that of lower wavelength step by step. The lower wavelength means the higher energy. The broader adsorption means the higher efficiency for energy adsorption and more e- and h+ with higher energy were activated to photocatalytically degrade dyes. This provides new potential to explore nanocomposites for efficient photo-driven degradation of organic dyes under visible light irradiation.
Databáze: OpenAIRE