A comparative study about the influence of metal ions (Ce, La and V) doping on the solar-light-induced photodegradation toward rhodamine B. Issue 3 (September 2015)

• Record Type: Journal Article
• Authors: Wang, Bin; Zhang, Guangxin; Sun, Zhiming; Zheng, Shuilin; Frost, Ray L.
• Is Part Of: Journal of environmental chemical engineering. Volume 3:Issue 3(2015:Sep.)
• Page Start: 1444
• Page End: 1451
• Publication Date: 2015-09
• Subjects: TiO2 -- Metal ions doping -- Sol–gel method -- Solar-light; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2015.05.007
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Three metal ions doped TiO2 particles were synthesized using facile sol–gel method. The optical absorption spectrum and photocatalysis kinetics for rhodamine B under solar light illumination of the as-prepared TiO2 catalyst are shown in the illustration. It indicates a gradual change in the colour and photo-degradation efficiency of different samples, which is accordance with the diffuse reflection spectra results shown in the figure. The effect of dopants existence on physical chemistry properties of the doped TiO2 particles was investigated. Highlights: The effects of different dopants on the TiO2 particles were investigated. The morphology, physiochemical properties and photoactivity were characterized. The existence of dopants in TiO2 matrix was systematically analyzed and discussed. The photocatalysis for rhodamine B were studied under solar light illumination. A comparative conclusion of metal ions doping was deduced. Abstract: Water contamination by the textile dye effluents has become a serious environmental issue, which are threatening to the human health and biological diversity. The TiO2 photocatalysis has been proven to be used to remove textile dyes in water. In order to improve its solar-light activity, three metal ions, including cerium (Ce), lanthanum (La) and vanadium (V), were selected as dopants to prepare metal ions doped TiO2 particles by sol–gel method. The synthesized particles were characterized by X-ray diffraction, field scanning electron microscopy, UV–vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. Through the physicochemical properties of the resulting metal ions doped TiO2 particles, we found that characteristics of dopants could strongly affect the crystalline phase and crystallite size, the optical absorption spectrum and the bandgap energy of the modified TiO2 catalysts, and consequently influence the photocatalytic ability. We investigated the link between dopant's characteristics and photoactivity of the doped catalysts, and deduced that the existence of dopant in the modified catalysts is crucial. In the case of Ce or La doping, the dopants homogeneously dispersed on the surface of TiO2 particles as oxides and interacted with TiO2 particles via REOTi bond. Nevertheless, the V species successfully entered the TiO2 lattice and substituted for Ti 4+ due to its similar ionic radius with Ti. The photocatalytic activities of Ce-, La-, or V-doped TiO2 photocatalysts were evaluated by the degradation of rhodamine B under simulated solar-light illumination. In our case, only the doping of Ce or V could drive efficient solar-light activity. The bandgap energy of 1.0%-Ce–TiO2 was narrowed to 2.70 eV and the removal ratio for dye could raise up to 83% with a relatively high calcination temperature.