Title: Characterisation and photocatalytic activity of Ag-modified BiVO₄ catalyst under visible light irradiation

Authors: Sheng Yin, Hua-ming Li, Ling Liu, Hui Xu, Yuan-guo Xu, Cheng-tang Liu

Addresses: School of Chemistry and Chemical Engineering, Jiangsu University, Jiangsu Zhenjiang 212013, China. ' School of Chemistry and Chemical Engineering, Jiangsu University, Jiangsu Zhenjiang 212013, China. ' School of Chemistry and Chemical Engineering, Jiangsu University, Jiangsu Zhenjiang 212013, China. ' School of Environment, Jiangsu University, Jiangsu Zhenjiang 212013, China. ' School of Environment, Jiangsu University, Jiangsu Zhenjiang 212013, China. ' School of Environment, Jiangsu University, Jiangsu Zhenjiang 212013, China

Abstract: The Ag-BiVO₄ photocatalysts were synthesised by impregnation/calcination method and characterised by powder X-ray diffraction (XRD), scanning election microscope (SEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (DRS). The photocatalytic activities of Ag-modified BiVO₄ were evaluated by N-demethylation of methylene blue (MB) under visible light irradiation (λ > 400 nm). The influence of Ag content and Ag-BiVO₄ calcination temperature on the photodegradation activity was studied. The results demonstrated that the photocatalytic degradation efficiency of MB was more than 99% using Ag-BiVO₄ within 3 hrs under visible light irradiation. The presence of Ag significantly enhanced the MB degradation efficiency under visible light irradiation and the optimal content of Ag was 3 wt.%. It was confirmed that the Ag-BiVO₄ calcination temperature was very important for the photocatalytic activity and the highest photodegradation efficiency of MB was obtained when the calcination temperature was 100°C. The UV-vis spectral analysis showed that blue shift resulting from N-demethylation of MB occurred along with oxidative degradation.

Keywords: Ag-BiVO4; photocatalysis; visible light irradiation; bismuth vanadate; silver; photodegradation; calcination temperature.

DOI: 10.1504/IJMSI.2011.039048

International Journal of Materials and Structural Integrity, 2011 Vol.5 No.1, pp.77 - 89

Published online: 27 Nov 2014 *

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