Efficient photocatalytic degradation of dyes over hierarchical BiOBr/β-Co(OH)2/PVP multicomponent photocatalyst under visible-light irradiation
writer：W. Li, P. Li, Y. Liu, B. Zhang, H. Zhang, W. Geng, Q. Zhang
keywords：bismuth, cobalt, dyes/pigments, photochemistry, semiconductors
source：期刊
specific source：https://onlinelibrary.wiley.com/doi/abs/10.1002/cctc.201500845
Issue time：2015年
A novel visible-light driven BiOBr/β-Co(OH)2/PVP (PVP=polyvinylpyrrolidone) hierarchical multicomponent photocatalyst assembled in nanosheets was synthesized by a simple one-pot
solvothermal synthesis. The as-prepared photocatalyst wascharacterized by field-emitting scanning electron microscopy,transmission electron microscopy, N2 adsorption–desorption analysis, FTIR spectroscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction analysis, X-ray photoelectron spectroscopy, UV/Vis diffuse reflectance spectra, and inductivelycoupled plasma atomic emission spectrometry. This researchshows that the formation of the p–n heterojunction would bevery conducive to effectively inhibit the recombination of thephotoexcited electron–hole pairs and enhance the photoactivity significantly. Owing to its narrow band-gap energy(=2.49 eV) and fast interfacial charge migration, this novelphotocatalyst can efficiently absorb visible light and shows an improved ability for utilizing light energy. Although both β-Co(OH)2 and BiOBr alone exhibit little photoactivity for the degradation of dyes, the BiOBr/β-Co(OH)2/PVP hierarchical multicomponent photocatalyst exhibits unexpected, surprisingly high photoactivity and stability in degrading dyes in aqueous solution at moderate Co/Bi molar ratio and moderate PVP addition. The catalyst’s photoactivity is approximately 9.7 times of that of β-Co(OH)2 and 3.2 times of that of BiOBr. This unusual photoactivity mainly arises from the synergetic chemical coupling effects between BiOBr, β-Co(OH)2, and PVP. The excellent photoactivity and photostability of this hierarchical multicomponent photocatalyst make it a promising photocatalyst under visible-light response. Beyond that, this novel photocatalyst can be reused many times without significant loss of its activity.
ChemCatChem 2015, 7, 4163 – 4172