Preparation of Zno-Cr2O3 Composites by a Sol-Gel Method and their Photocatalytic Activities

2012 ◽  
Vol 151 ◽  
pp. 365-367 ◽  
Author(s):  
Kai Yuan Gu ◽  
Zhan En Peng ◽  
Jin Hua Feng ◽  
Feng Qiang Sun

The ZnO-Cr2O3 composites with different complex proportion were prepared by a sol-gel method. The mol ratio of Zn and Cr element could be tuned by controlling the concentration of the precursors. These composites showed photocatalytic activities in degradation of methyl orange under the irradiation of 300W mercury lamp. And the activities regularly varied with the mol ratio of Zn and Cr. When n(Zn):n(Cr)=10:1, a composite with best photocatalytic activity could be obtained.

2011 ◽  
Vol 287-290 ◽  
pp. 2199-2202
Author(s):  
Gui Qin Hou ◽  
Wen Li Zhang ◽  
Shui Jing Gao ◽  
Xiao Yan Wang

The ZnFe2O4 and TiO2 nanocomposite films was prepared by Sol-Gel method on conductive glass, and the influence factors of it’s photoelectrocatalytic performence such as the film layer, pole and voltage was investigated. The results indicated that: the photocatalytic effects of composite films with ZnFe2O4+ TiO2+ ZnFe2O4 was the best. The decomposing ratio of methyl orange with the photoelectrocatalysis of composite films at voltage 0.2-6V all increased unstably.At the same time, the distance from films to pole plank also had the effects on the photocatalytic activities of the films.


2011 ◽  
Vol 239-242 ◽  
pp. 1850-1853
Author(s):  
Shu Kai Zheng

A series of TiO2 thin films with and without Ce3+ doping were successfully obtained on microscope glass slides by sol-gel method. The photocatalytic activities of the pure TiO2 and Ce3+-doped TiO2 thin films were evaluated by the degradation of rhodamine B solution. The effects of both Ce3+ contents and annealing temperatures on the photocatalytic activities of the samples were examined. The results indicated that the TiO2 thin film with an atomic ratio of Ti:Ce=5:1 annealed at 300°C had a higher photocatalytic activity among the samples.


2011 ◽  
Vol 197-198 ◽  
pp. 926-930
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Chen Zhi Jiang

FeVO4photocatalysts were synthesized via a surfactant-assisted sol-gel method and characterized with X-ray diffraction (XRD), scanning electron microsoope (SEM)and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns of no-surfactant-assisted, PEG-assisted, CTAB-assisted and SDS-assisted FeVO4, indicate that diffraction peaks can be well indexed as triclinc FeVO4. And the crystalline sizes of samples were evaluated as 113, 69, 66, 76 nm for FVO, FVO-PEG, FVO-CATB and FVO-SDS respectively.The addition of surfactant woul greatly affect the morphology of FeVO4photocatalysts, which can lead to different photocatalytic activities between them. In the experimental conditions used, the PEG-assisted FeVO4product had a much higher photocatalytic activity (the photodegradation rate was about 77% or so in 14h) than the other three products.


2011 ◽  
Vol 233-235 ◽  
pp. 1655-1658
Author(s):  
Shu Kai Zheng

TiO2 and different contents Fe3+-doped TiO2 thin films were successfully obtained on microscope glass slides by Sol-Gel method. Then the photocatalytic activities of the samples were evaluated by the degradation of Rhodamine B dye solution. The effects of both annealing temperatures and Fe3+ contents on the photocatalytic activities of TiO2 thin films were examined. The results indicated that the sample with an atomic ratio of Ti:Fe=7:3 annealed at 500°C had a higher photocatalytic activity.


2017 ◽  
Vol 50 ◽  
pp. 57-71 ◽  
Author(s):  
Xiao Nan Xu ◽  
Qiu Ping Zhang ◽  
Brain T.M. Ong ◽  
Huan Yuan ◽  
Yu Chen ◽  
...  

Utilizing zinc acetate as precursor, and monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) as stabilizers, respectively, ZnO nanoparticles with uniformly distributed grains were synthesized by sol-gel method at different sintering temperatures. Analysis of the degradation of methyl orange by photocatalysis shows that utilizing MEA as the stabilizer and 550°C as the sintering temperature results in smaller grain size, greater surface-to-volume ratio, and a density of surface defects suitable for a photocatalyst. The greatest photocatalytic degradation of methyl orange was achieved under UV irradiation. Based on our microstructural analysis and photocatalysis, the microstructure of ZnO particles and, in turn, their photocatalytic effect are affected significantly by the stabilizer type and the sintering temperature.


Author(s):  
Chelaramani K. ◽  
Varshney R. ◽  
Bhardwaj A.

The TiO2 and Ag and Zn doped TiO2 nanoparticles were synthesized by sol-gel method.The sol-gel method is one of the versatile method to prepare doped and co-doped nanoparticles. sol gel method has emerged as simpler and better option than physical and chemical procedures as it is fast, clean and eco-friendly alternative that does not involve any costly instruments .Synthesis of doped and co-doped nanoparticles having good photocatalytic activity have great potential for the degradation of dye. We have tried to develop new effective antimicrobial reagents with good photocatalytic activities which are not resistant to disease causing microbes.


2012 ◽  
Vol 472-475 ◽  
pp. 157-160
Author(s):  
Jun Liu ◽  
Zhi Bing Xu

Ag doped TiO2 was formed on the surface of carbon nanotube(CNT) by the sol-gel method, and characterized by TEM, XRD. The photocatalytic activity of the Ag-TiO2 /CNT was evaluated in degradation of methyl orange with a 300 W high pressure mercury lamp. Effect of Ag doping quantity on the photocatalytic activity of the photocatalys was investigated.The photocatalytic experiment indicated that the photocatalytic activity was firstly improved and then decreased with an increase of amount of Ag doped in TiO2 nanoparticles,the optimal doping quantity was 0.8% silver ( mass fraction of TiO2), methyl orange could be degraded 99.3 % by Ag-TiO2/CNT under the optimal conditions after 120min.


2019 ◽  
Vol 6 (10) ◽  
pp. 191156
Author(s):  
Yongsheng Ling ◽  
Guang Wang ◽  
Ting Chen ◽  
Xionghui Fei ◽  
Song Hu ◽  
...  

BaF 2 –TiO 2 nanocomposite material (hereinafter called the composite) was prepared by a sol–gel method. The composite surface area, morphology and structure were characterized by Brunauer–Emmett–Teller method, X-ray diffraction analysis and a scanning electron microscopy. The results showed that BaF 2 and TiO 2 form a PN-like structure on the surface of the composite. Composites were used to catalyse the degradation of methyl orange by irradiation with ultraviolet light, γ-rays and an electron beam (EB). It was demonstrated that the composite is found to be more efficient than the prepared TiO 2 and commercial P25 in the degradation of methyl orange under γ-irradiation. Increasing the composite catalyst concentration within a certain range can effectively improve the decolorization rate of the methyl orange solution. However, when the composite material is used to catalyse the degradation of organic matter in the presence of ultraviolet light or 10 MeV EB irradiation, the catalytic effect is poor or substantially ineffective. In addition, a hybrid mechanism is proposed; BaF 2 absorbs γ-rays to generate radioluminescence and further excites TiO 2 to generate photo-charges. Due to the heterojunction effect, the resulting photo-charge will produce more active particles. This seems to be a possible mechanism to explain γ-irradiation's catalytic behaviour.


2011 ◽  
Vol 214 ◽  
pp. 6-10
Author(s):  
Wen Jie Zhang ◽  
Ke Xin Li ◽  
Yang Yu

The ammonia phosphate treated HZSM-5 zeolite was used as support for TiO2 prepared by sol-gel method. Adsorption and photocatalytic activity of the zeolite, adsorption of the loaded TiO2, and the optimum TiO2 loading percentage were studied. The zeolite can concentrate methyl orange solution after adsorbing water and possesses no obvious photocatalytic activity. The solution reached its adsorption equilibrium after 20 min when using TiO2 loaded on HZSM-5. In the TiO2 loading range from 10% to 70%, the dye decoloration rate increased constantly from 20% to 36.2%. The activity of the TiO2 was enhanced after loading with the optimum loading percent of 70%. During the whole 180 min of irradiation, TiO2/HZSM-5 showed enhanced methyl orange decoloration activity.


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