Sonochemical Decolourisation of Reactive Blue 21 and Acid Red 114 in the Presence of TiO2 and Rare Earths

2012 ◽  
Vol 734 ◽  
pp. 237-246 ◽  
Author(s):  
Pankaj ◽  
Shikha Goyal

The ultrasonic decolourisation of two commonly used textile dyes, Acid Red 114 (AR 114) and Reactive Blue 21 (RB 21), with different chromophoric groups, azo and phthalocyanine respectively, has been studied using TiO2 (consisting of mixture of crystalline and amorphous phases) in the presence of rare earths ions (Pr3+, Ce4+). The characterisation of TiO2 has been done through X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, diffuse reflectance spectroscopy (DRS) and N2 adsorption techniques. The decolourisation of AR 114 was faster than for RB 21 under all the experimental conditions. Almost complete decolourisation of both dyes was achieved in 5 min in the presence of US+TiO2+Ce. Ce4+ was found to be more effective than Pr3+. The decolourisation reaction followed second order kinetics. The effects of initial dye concentration and amount of TiO2 on the decolourisation of dyes have been found to be in the order; US+TiO2+Ce > US+TiO2+Pr > US+Ce > US+Pr > US+TiO2 > TiO2 >US. The decolourisation rate increased with increase in TiO2 amount and decreased with increase in initial dye concentration.

2017 ◽  
Vol 10 (02) ◽  
pp. 1750004 ◽  
Author(s):  
LiZhen Ren ◽  
DongEn Zhang ◽  
Xiao Yun Hao ◽  
Xin Xiao ◽  
Jun Yan Gong ◽  
...  

Bi2S3/SnS2 heterostructured photocatalysts were synthesized from BiOI, SnCl[Formula: see text]5H2O and NH2CSNH2 using an economic and simple hydrothermal method. The as-synthesized samples were characterized by X-ray diffraction, scanning electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy. The photodegradation activities of the Bi2S3/SnS2 heterostructured photocatalysts were estimated by degrading rhodamine B under simulated sunlight supplied by irradiating with a 350[Formula: see text]W Xe lamp. Bi2S3/SnS2 photocatalysts were prepared using varying percentages of Bi2S3. The sample containing 13% Bi2S3 had the most efficient photocatalyst performance among the tested samples. The photocatalytic mechanism involves heterojunctions formed in the Bi2S3/SnS2, which promoted effective separation of photoinduced electrons and holes.


2015 ◽  
Vol 68 (10) ◽  
pp. 1562 ◽  
Author(s):  
Fengjun Zhang ◽  
Guosheng Xiao ◽  
Wei Lu ◽  
Tianye Wang ◽  
Limin Xuan ◽  
...  

Eu-Doped Bi2O3/CeO2 composites were successfully synthesized by a facile sol–gel–calcination route. The as-prepared composites were prepared with different molar ratios of Bi/Ce/Eu by the sol–gel route, and then calcined at 500°C for 2 h. The photocatalytic efficiencies of all composites were tested by degradation of methyl orange (MO) under visible light irradiation. The result suggested that the best composite is the one that was prepared with a Bi/Ce/Eu mole ratio of 8 : 8 : 1, and achieved a MO degradation rate of nearly 98.5 % within 2 h of irradiation. The as-prepared composites were characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The X-ray diffraction and scanning electron microscopy results suggested that Eu doping may have led to some lattice distortion and particle aggregation that enhanced the photocatalytic activity of the photocatalyst. The UV-visible diffuse reflectance spectroscopy and photoluminescence spectroscopy results showed that Eu-doped Bi2O3/CeO2 exhibited higher visible light response properties and enhanced separation of the photogenerated electron–hole pairs, which is the main reason for the higher photocatalytic activity. In general, this study could provide a facile route to synthesize Eu-doped Bi2O3/CeO2 composites with enhanced photocatalytic activity by a sol–gel–calcination route for environmental purification.


2014 ◽  
Vol 881-883 ◽  
pp. 1101-1104 ◽  
Author(s):  
Min Jie Zhou ◽  
Peng Cui

In this work, flower-like ZnIn2S4 microspheres were synthesized using a solvothermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic activity of the ZnIn2S4 microspheres was investigated. The ZnIn2S4 microspheres exhibit much higher photocatalytic activity than pure P25 TiO2.


2014 ◽  
Vol 875-877 ◽  
pp. 34-38 ◽  
Author(s):  
Chong Fai Kait ◽  
B. Abu Kassim Mohd Eqram ◽  
Bt. Mohd Zaid Hayyiratul Fatimah

A series of Cu-Fe/TiO2photocatalysts were prepared and calcined at 400°C and 500°C for 1 h. The photocatalysts were characterized using diffuse reflectance spectroscopy (DR-UV-Vis), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The performance for sulfur removal was carried out using model oil containing 100 ppm S (from dibenzothiophene). The highly dispersed Cu-Fe/TiO2photocatalyst displayed mainly spherical shaped particles. The best performing photocatalyst was 0.8wt% Cu-Fe loading and calcined at 400°C (0.8wt400) giving 18% sulfur removal. The band gap for 0.8wt400 was lowered to 2.96 eV compared to 3.21 eV for TiO2.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xiaoyang Wang ◽  
Fuchun Zhang ◽  
Yanning Yang ◽  
Yu Zhang ◽  
Lili Liu ◽  
...  

Nano-BiOBr photocatalysts were successfully prepared by hydrothermal synthesis using the ethylene glycol solution. The nano-BiOBr photocatalysts were characterized and investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), photoluminescence (PL), and UV-vis diffuse reflectance spectroscopy (UV-Vis DRS), and the catalytic ability toward photodegradation of rhodamine B (RhB) was also explored. The results showed that the crystallinity of the nano-BiOBr photocatalyst decreased with the increase of the concentration, while it increased with the amount of the applied deionized water. The morphology of the nano-BiOBr photocatalyst changed from microspheres to cubes and then to a mixture of microspheres and flakes with the increasing of the concentration and from microspheres to flakes with the addition of the deionized water. The results indicated that the concentration and solvents have an essential influence on the bandgap energy values of the nano-BiOBr photocatalyst, and photocatalyst showed an excellent photocatalyst activity toward photodegradation of RhB. The degradation yields of photocatalyst decreased with the increase of the concentration and increased with the addition of the deionized water. PL intensity of photocatalyst increased with the increase of the concentration and weakened with the addition of the deionized water.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yunling Zou ◽  
Xianshou Huang ◽  
Tao Yu ◽  
Xiaoqiang Tong ◽  
Yan Li ◽  
...  

Abstract Cu-doped TiO2 having a brookite phase and showing enhanced visible light photocatalytic activity was synthesized using a mild solvothermal method. The as-prepared samples were characterized by various techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity of Cu-doped brookite TiO2 nanoparticles was evaluated by photodegradation of methylene blue under visible light irradiation. The X-ray diffraction analysis showed that the crystallite size of Cu-doped brookite TiO2 samples decreased with the increase of Cu concentration in the samples. The UV-Vis diffuse reflectance spectroscopy analysis of the Cu-doped TiO2 samples showed a shift to lower energy levels in the band gap compared with that of bare phase brookite TiO2. Cu doped brookite TiO2 can obviously improve its visible light photocatalytic activity because of Cu ions acting as electron acceptors and inhibiting electron-hole recombination. The brookite TiO2 sample with 7.0 wt.% Cu showed the highest photocatalytic activity and the corresponding degradation rate of MB (10 mg/L) reached to 87 % after visible light illumination for 120 min, much higher than that of bare brookite TiO2 prepared under the same conditions (78 %).


2012 ◽  
Vol 476-478 ◽  
pp. 1882-1888
Author(s):  
Ke Lei Zhang ◽  
Rui Jie Zhao ◽  
Qian Kun Lei ◽  
Yan Chun Hu

Spinel Zn2SnO4 photocatalysts have been prepared by the solid state reaction. as-prepared samples were characterized by power X-ray diffraction, scanning electron microscope, UV-vis diffuse reflectance spectroscopy and photocatalytic activity measurement. The results show that the reaction temperature have significant effects on the Zn2SnO4 photocatalytic activity . It has also been found that the distribution of the cations in Zn2SnO4 crystal lattice changes with the increase of calcination temperature, causing the local structural fine adjustment that associated with the photocatalytic properties.


2014 ◽  
Vol 556-562 ◽  
pp. 362-365 ◽  
Author(s):  
Guang Jian Xing ◽  
Hong Li Guo ◽  
Peng Li ◽  
Guang Ming Wu

In this study, CdLa2S4hierarchical microspheres have been successfully synthesized through a hydrothermal method without any surfactants or templates. The crystal structure, morphology, and optical properties of the products were characterized by X-ray diffraction, scanning electron microscopy, and UV-vis diffuse reflectance spectroscopy. The results showed that the reaction time affects the structure and morphology of the CdLa2S4products. Finally, the CdLa2S4microspheres showed perfect photocatalytic properties for the degradation of the methyl orange solutions.


2010 ◽  
Vol 150-151 ◽  
pp. 1726-1731 ◽  
Author(s):  
Kornkanok Ubonchonlakate ◽  
Lek Sikong ◽  
Tienchai Tontai ◽  
Fumio Saito

The photocatalytic Ag and Ni doped TiO2 films were prepared by sol-gel method and coated on glass fiber roving. The films were calcined at 500 °C for 1 hour with a heating rate of 10°C/min. The surface morphology and properties of synthesized TiO2 films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and UV-vis diffuse reflectance spectroscopy (DRS). The results show that TiO2-1Ag and TiO2-1Ag-1Ni films give rapidly kill P.aeruginosa bacteria under UV irradiation and TiO2-1Ni films give well kill P.aeruginosa bacteria under visible light.


2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.


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