scholarly journals Probing Photocatalytic Characteristics of Sb-DopedTiO2under Visible Light Irradiation

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Lingjing Luo ◽  
Tianfeng Li ◽  
Xia Ran ◽  
Pan Wang ◽  
Lijun Guo

Sb-doped TiO2nanoparticle with varied dopant concentrations was synthesized using titanium tetrachloride (TiCl4) and antimony chloride (SbCl3) as the precursors. The properties of Sb-doped TiO2nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), fluorescence spectrophotometer, and Uv-vis spectrophotometer. The absorption edge of TiO2nanoparticles could be extended to visible region after doping with antimony, in contrast to the UV absorption of pure TiO2. The results showed that the photocatalytic activity of Sb-doped TiO2nanoparticles was much more active than pure TiO2. The 0.1% Sb-doped TiO2nanoparticles demonstrated the best photocatalytic activity which was better than that of the Degussa P25 under visible light irradiation using terephthalic acid as fluorescent probe. The effects of Sb dopant on the photocatalytic activity and the involved mechanism were extensively investigated in this work as well.

2014 ◽  
Vol 787 ◽  
pp. 35-40 ◽  
Author(s):  
Xiao Yan Zhou ◽  
Peng Wei Zhou ◽  
Hao Guo ◽  
Bo Yang ◽  
Ru Fei Ren

The p-n junction photocatalysts, p-CuO (at. 0-25%)/n-ZnO nanocomposite were prepared through hydrothermal method without using any organic solvent or surfactant. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-Ray spectroscopy, and UV-vis spectroscopy. The results demonstrated that the CuO/ZnO nanocomposite presented a two-dimensional morphology composed of sheet-like ZnO nanostructures adorned with CuO nanoparticles. The photocatalytic activity of CuO/ZnO with different Cu/Zn molar rations and pure ZnO synthesized by the identical synthetic route were evaluated by degrading methylene blue (MB) dye under UV-visible light irradiation. The CuO/ZnO with Cu/Zn molar ratio of 4% exhibits the highest photocatalytic activity compared that of the other photocatalysts under the identical conditions. It is mainly attributed to the increased charge separation rate in the nanocomposite and the extended photo-responding range.


2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue

Pure anatase TiO2 photocatalysts with different Ag contents were prepared via a simple sol-gel method. The as-prepared anatase Ag-doped TiO2 photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectra, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermal gravity and differential thermal analysis, scanning electron microscopy and N2 adsorption–desorption measurements (BET). Compared with pure TiO2, Ag-doped anatase TiO2 photocatalysts exhibited not only increases in light absorption in the visible region, the separation efficiency of electron–hole pairs and surface area, but also inhibition of the titania phase transition from anatase to rutile. Photoreduction results showed that Ag-doped anatase TiO2 photocatalysts have greatly improved photocatalytic activity, compared with pure TiO2, and the reduction of Cr(VI) under visible light irradiation was much higher than that of pure TiO2. The optimum Ag content was 1.0 mol%, which led to the complete reduction of Cr(VI) under visible light irradiation (λ > 420 nm) for 4 h. The enhanced photocatalytic activity was attributed to the synergic effect of the pure anatase structure, and the increased light absorption in the visible region, separation efficiency of electron–hole pairs and atomic ratio of Ag0:Ag2O.


2014 ◽  
Vol 807 ◽  
pp. 101-113 ◽  
Author(s):  
J. Theerthagiri ◽  
R.A. Senthil ◽  
J. Madhavan ◽  
B. Neppolian

The graphitic carbon nitride (g-C3N4) materials have been synthesized from nitrogen rich precursors such as urea and thiourea by directly heating at 520 °C for 2 h. The as-synthesized carbon nitride samples were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) and particle size analysis. The photoelectrochemical measurements were performed using several on-off cycles under visible-light irradiation. The x-ray diffraction peak is broader which indicates the fine powder nature of the synthesized materials. The estimated crystallite size of carbon nitrides synthesized from urea (U-CN) and thiourea (T-CN) are 4.0 and 4.4 nm respectively. The particle size of U-CN and T-CN were analysed by particle size analyser and were found to be 57.3 and 273.3 nm respectively. The photocatalytic activity for the degradation of the textile dye namely, direct red-81 (DR81) using these carbon nitrides were carried out under visible light irradiation. In the present investigation, a comparison study on the carbon nitrides synthesized from cheap precursors such as urea and thiourea for the degradation of DR81 has been carried out. The results inferred that U-CN exhibited higher photocatalytic activity than T-CN. The photoelectrochemical studies confirmed that the (e--h+) charge carrier separation is more efficient in U-CN than that of T-CN and therefore showed high photocatalytic degradation. Further, the smaller particle size of U-CN is also responsible for the observed degradation trend.


2016 ◽  
Vol 35 (9) ◽  
pp. 853-856 ◽  
Author(s):  
Yi Shen ◽  
Xiaomin Wang ◽  
Guifu Zuo ◽  
Fengfeng Li ◽  
Yanzhi Meng

AbstractMonoclinic BiVO4 photocatalyst was successfully synthesized by hydrothermal method under appropriate temperature. The photocatalytic performance of BiVO4 was improved by calcining at appropriate temperature. The structural and morphological properties of the synthesized BiVO4 photocatalysts were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It is confirmed that the photocatalytic activity of the prepared catalysts was evaluated by the photodegradation of RhB under visible-light irradiation. BiVO4 calcined under appropriate temperature exhibited higher photocatalytic activity than uncalcined BiVO4 under visible light irradiation because calcination might effectively increases the purity of monoclinic bismuth vanadate.


Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Sarah Aghakhaninejad ◽  
Rahmatollah Rahimi ◽  
Solmaz Zargari

In this work, BiVO4–graphene photocatalyst was prepared by a facile one-step hydrothermal method and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The photocatalytic activity of this compound was investigated by destruction of methyl orange (MO) under visible light irradiation. The photodegradation results show that the prepared BVG compound has higher photocatalytic activity than the pure BiVO4 compound. This compound can degrade 98% of MO under visible light irradiation. This work indicates that BiVO4 compounds are excellent compounds for pollutant degradation under visible light irradiation.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Pengyu Dong ◽  
Yan Hao ◽  
Peiyang Gao ◽  
Entian Cui ◽  
Qinfang Zhang

Ag3PO4triangular prism was synthesized by a facile chemical precipitation approach by simply adjusting external ultrasonic condition. The as-synthesized Ag3PO4triangular prism was characterized by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectra, and ultraviolet-visible diffuse reflectance (UV-vis DRS) absorption spectra. The photocatalytic activity of Ag3PO4triangular prism was evaluated by photodegradation of organic methylene blue (MB), rhodamine B (RhB), and phenol under visible light irradiation. Results showed that Ag3PO4triangular prism exhibited higher photocatalytic activity than N-doped TiO2and commercial TiO2(P25) under visible light irradiation.


Author(s):  
Yaping Guo ◽  
Jianyang Sun ◽  
Hui Chang ◽  
Xu Zhao

A simple, effective and environmental-friendly method was adopted for enhancing the photocatalytic activity of g-C3N4 in the reduction of aqueous Cr(Ⅵ) under visible-light irradiation. The enhancement was achieved via treatment of g-C3N4 in organic solvent with addition of NaOH particles by ultrasonic process for two hours. The results demonstrated that the treated g-C3N4 exhibited much higher photocatalytic activity than pristine g-C3N4 in the reduction of Cr(VI) . Under visible light irradiation for 120 min, the reduced ratios of Cr(VI) with the initial concentration of 50 mg/L in the presence of the treated g-C3N4and pristine g-C3N4 were 100% and 37.1%, respectively. With the addition of fulvic acid, Cr(VI) was efficiently removed at 40 min. Based on the characterization results of the structures and other physiochemical properties of the treated g-C3N4 and pristine g-C3N4 by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV Vis diffuse reflectance, the possible reasons responsible for the enhanced photocatalytic activity of the treated g-C3N4 were proposed. The yield and mechanism of different exfoliation methods were compared by semi-quantitative method.


2002 ◽  
Vol 17 (6) ◽  
pp. 1419-1424 ◽  
Author(s):  
Zhigang Zou ◽  
Jinhua Ye ◽  
Hironori Arakawa

The effect of Ni substitution on the structure and photocatalytic H2 and O2 evolutions of InTaO4 under visible light irradiation (λ > 420 nm) from aqueous CH3OH/H2O and AgNO3/H2O solutions were investigated. The photocatalysts were prepared by the solid-state reaction method and characterized by powder x-ray diffraction and Rietveld structure refinement. These photocatalysts crystallize in the same wolframite structure, but lattice parameters decrease with increase of x in In1−xNixTaO4 (0 ≤x ≤ 0.2). The photocatalytic activity changed with the variation of x in In1−xNixTaO4and the photocatalyst at x = 0.1 showed the highest activity, which increased 8 times compared with nonsubstituted photocatalyst.


2018 ◽  
Vol 914 ◽  
pp. 168-174
Author(s):  
Jun Qing Chang ◽  
Yan Zhong ◽  
Chao Hao Hu ◽  
Zong Wei Ji ◽  
Yi Fan Li ◽  
...  

The smooth spherical BiOCl photocatalyst was synthesized successfully by a facile solvothermal method and further characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer and UV-Vis diffuse reflectance spectra techniques. The photocatalytic activity of as-prepared photoctalyst was evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation (λ>420 nm). The results showed that the BiOCl with smooth spherical morphology exhibits an excellent photocatalytic activity and stability. RhB was thoroughly degraded after 60 min of visible light irradiation.


2011 ◽  
Vol 236-238 ◽  
pp. 2102-2105
Author(s):  
Long Feng Li ◽  
Mao Lin Zhang

The nano-scale Cu2O-TiO2 couple oxide photocatalyst was successfully synthesized by the homogeneous hydrolysation, followed by the solvothermal crystallization and ethylene glycol-thermal reduction process, respectively. The obtained photocatalysts were characterized by X-ray diffraction (XRD), showing that the crystal phase composition and the crystal size of the prepared photocatalyst were affected by the ethylene glycol-thermal reduction temperature. The photocatalytic activity of Cu2O-TiO2 was also evaluated by the degradation of methyl orange (MO) as a model compound. The results showed that the prepared Cu2O-TiO2 exhibited higher photocatalytic activity for the decomposition of MO than the pure Cu2O and the commercial Degussa P25 TiO2 under visible light irradiation.


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