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Journal of Advanced Ceramics 2020年第1期9卷 107-122页

作者： Abbas Sadeghzadeh-Attar Department of Metallurgy and Materials Engineering University of KashanP.O.Box.87317-53153Ghotb Ravandi Blvd.KashanIran

In this paper,a comparative study on the photocatalytic degradation of the Rhodamine B(Rh B)dye as a model compound using N–Fe codoped Ti O2 nanorods under UV and visible-light(λ≥420 nm)irradiations has been *** O2 photocatalysts were fabricated as aligned nanorod arrays by liquid-phase deposition process,annealed at different temperatures from 400 to 800℃.The effects of annealing temperature on the phase structure,crystallinity,BET surface area,and resulting photocatalytic activity of N–Fe codoped Ti O2 nanorods were also *** degradation studies confirmed that the nanorods annealed at 600℃composed of both anatase(79%)and rutile phases(21%)and offered the highest activity and stability among the series of nanorods,as it degraded 94.8%and 87.2%Rh B in 120 min irradiation under UV and visible-light,*** 600℃,the photocatalytic performance of nanorods decreased owning to a phase change,decreased surface area and bandgap,and growth of Ti O2 crystallites induced by the annealing *** is hoped that this work could provide precious information on the design of 1 D catalyst materials with more superior photodegradation properties especially under visible-light for the further industrial applications.

关键词： N–Fe codoped TiO2 nanorods liquid-phase deposition annealing temperature photocatalytic degradation

photocatalytic degradation of methyl orange by polyoxometalates supported on yttrium-doped TiO_2

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Journal of Rare Earths 2011年第9期29卷 866-871页

作者：王亚军陆科呈冯长根 State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

A series of novel photocatalysts, H3PW12O40-Y-TiO2 nanocomposites with different H3PW12O40 loading levels （10%-40%） were prepared by impregnation method. And the Y-TiO2 support, doped with yttrium, was synthesized via sol-gel technique. The prepared catalysts were characterized by Fourier transform infrared spectroscopy （FT-IR）, powder X-ray diffraction （XRD）, nitrogen adsorption-desorption analysis and scanning electron microscopy （SEM）. The processes allowed obtaining Keggin structure and crystallized anatase with large BET surface area as well as uniform distribution. The effects of H3PW12O40 loadings, catalyst dose, initial pH and concentration of dye solution on the degradation kinetics of methyl orange under UV light （λ≥365 nm） were discussed. Kinetics studies showed that the photocatalytic degradation of methyl orange fitted the apparent first-order reaction. Methyl orange was totally degraded in 21 min under optimum conditions： 20% loading, 0.03 g dose and pH 1.0. The catalyst was stable and easily to be separated from reaction system for recovery.

关键词： polyoxometalates titanium dioxide rare earths photocatalytic degradation kinetics azo dyes

photocatalytic degradation of perfluorooctanoic acid with β-Ga_2O_3 in anoxic aqueous solution

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Journal of Environmental Sciences 2012年第4期24卷 774-780页

作者： Baoxiu Zhao Mou Lv Li Zhou School of Environmental and Municipal Engineering Qingdao Technological UniversityQingdao 266033China State Key Joint Laboratory of Environment Simulation and Pollution Control Department of Environmental Science and EngineeringTsinghua UniversityBeijing 100084China

Perfluorooctanoic acid （PFOA） is a new-found hazardous persistent organic pollutant, and it is resistant to decomposition by hydroxyl radical （HO.） due to its stable chemical structure and the high electronegativity of fluorine. photocatalytic reduction of PFOA with β-Ga2O3 in anoxic aqueous solution was investigated for the first time, and the results showed that the photoinduced electron （ecb） coming from the β-Ga2O3 conduction band was the major degradation substance for PFOA, and shorter-chain perfluorinated carboxylic acids （PFCAs, CnF2n＋1COOH, 1 ≤ n ≤ 6） were the dominant products. Furthermore, the concentration of F- was measured by the IC technique and defluorination efficiency was calculated. After 3 hr, the photocatalytic degradation efficiency was 98.8% and defluorination efficiency was 31.6% in the presence of thiosulfate and bubbling N2. The degradation reaction followed first-order kinetics （k = 0.0239 min-1, t1/2 = 0.48 hr）. PFCAs （CnF2n＋xCOOH, 1 ≤ n≤ 7） were detected and measured by LC-MS and LC-MS/MS methods. It was deduced that the probable photocatalytic degradation mechanism involves ec-b attacking the carboxyl of CnF2n＋1COOH, resulting in decarboxylation and the generation of CnFzn＋1. The produced CnF2n＋1 reacted with H2O, forming CnF2n＋1OH, then CnF2n＋1OH underwent HF loss and hydrolysis to form CnF2,＋1COOH.

关键词： perfluorooctanoic acid β-Ga2O3 photocatalytic degradation defluorination photoinduced electron

photocatalytic degradation of bisphenol A using an integrated system of a new gas-liquid-solid circulating fluidized bed reactor and micrometer Gd-doped TiO_2 particles

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Journal of Environmental Sciences 2012年第7期24卷 1317-1326页

作者： Zhiliang Cheng Xuejun Quan Jinxin Xiang Yuming Huang Yunlan Xu Key Laboratory of Eco-environments in Three Gorges Reservoir Region(Ministry of Education of China) College of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400175China College of Chemistry and Chemical Engineering Chongqing University of TechnologyChongqing 400050China

A new gas-liquid-solid circulating fluidized bed photocatalytic reactor （GLSCFBPR） with internally placed multi-layered UV lamps was developed. Micrometer Gd-TiO2 particles and commercial nanometer P25-TiO2 were chosen as the photocatalysts, and the hazardous substance bisphenol A （BPA） was chosen as the model pollutant to investigate the performance of this new photocatalytic system. The results showed that the photocatalytic degradation efficiency of the micrometer Gd-TiO2 particles was similar to that of the nanometer P-25 particles at their respective optimum dosage but the former could be easily separated out by gravity. After investigating the effects of process parameters on the photocatalytic BPA degradation, the response surface method （RSM） was further used for process optimization. The interactions among process parameters, i.e., TiO2 concentration, superficial gas velocity and superficial liquid velocity were discovered and a related analysis was carried out to explore the underlying mechanism. A quadratic mathematic model was established and performed satisfactorily when used for prediction. The optimum conditions for this new process were as follows： TiO2 concentration 4.5 g/L, superficial gas velocity 7.83 x 10-3 m/sec and superficial liquid velocity 8.65 x 10-3 m/sec.

关键词： fluidized bed photocatalytic reactor Gd-doped titanium dioxide photocatalytic degradation bisphenol A

photocatalytic degradation of MO by complex nanometer particles WO_3/TiO_2

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Rare Metals 2006年第6期25卷 649-653页

作者： CUI Yumin Department of Chemistry Fuyang Normal College Fuyang 236041 China

Complex nanometer particles WO3/TiO2 were prepared using a sol-gel process and characterized using XRD spectra. The photocatalytic activity of TiO2 can be increased by doping W^6＋ with TiO2 because the doped W^6＋ that entered into the crystal lattices of TiO2 led to the formation of defects in the crystal lattices of TiO2 and thereby improved the photocatalytic activity of *** WO3 doped in TiO2 exceeded 3%, the excess W^6＋ did not enter into the crystal lattices of TiO2 but were uniformly dispersed in TiO2 or they covered the surface of TiO2, which reduced the effective illumination area of TiO2 and thereby lowered the photocatalytic activity of *** relationship among the composition of the catalyst, the amount of photocatalyst, the illumination time, and the decolorizing rate of methyl orange （MO） were discussed. The results show that the decolorizing rate of MO can reach 82.3% using WO3/TiO2 as the photocatalyst, with the composition of WO3/TiO2 -3：97, the mass of catalyst = 0.400 g, the initial concentration of MO = 20 mg/L, pH = 6.5, and the illumina- tion time = 7 h.

关键词： physical chemistry photocatalytic degradation methyl orange photocatalytic method titanium dioxide tung sten trioxide

photocatalytic degradation of the dye sulforhodamine-B: A comparative study of different light sources

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Journal of Environmental Sciences 2007年第1期19卷 97-102页

作者： FANG Yan-fen HUANG Ying-ping LIU De-fu HUANG Yang GUO Wei DAVID Johnson Center for Ecologic and Environmental Science Three Gorges University Yichang 443000 China Department of Chemistry and Environment Sciences Ferrum College VA 24088 USA

The photocatalytic degradation of dye pollutant sulforhodamine-B （SRB） in aqueous titanium dioxide （TiO2） dispersions was examined under three lighting regimes： UV light （330 nm〈λ〈 380 nm）, sunlight, and visible light （λ〉450 nm）, all investigated at pH=2.5. Total organic carbon （TOC） and chemical oxygen demand （CODer） assays show that the degradation rate of SRB is much higher when irradiated with UV and sunlight compared with visible light. The temporal concentration changes of SRB illustrated a first-order reaction and the rate constant, k, is 0.197 min^-1, 0.152 min^-1, 0.027 min^-1, respectively, under the three lighting conditions. The final mineralized products were amine compounds identified by infrared spectrophotometry. When irradiated with visible light, the photocatalytic degradation rate could be improved by lowering the H2O2 concentration and inhibited by increasing the H2O2 concentration, but results contrary to the above were obtained when UV light was used for irradiation.

关键词： TiO2 photocatalytic degradation sulforhodamine-B (SRB)

photocatalytic degradation of 4-tert-octylphenol in a spiral photoreactor system

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Journal of Environmental Sciences 2012年第9期24卷 1679-1685页

作者： Yanlin Wu Haixia Yuan Xiaoxuan Jiang Guanran Wei Chunlei Li Wenbo Dong Department of Environmental Science and Engineering Fudan University Shanghai 200433 Chint~ E-mail: wuyanlin2004@***

A spiral photoreactor system （SPS） was developed for the degradation of 4-tert-octylphenol （4-t-OP） in aqueous phase. 4-t-OP was previously considered as a endocrine disrupting compound frequently present in water. The direct photodegradation reaction caused by the SPS was found to accord with the characteristic of apparent first-order reaction with reaction rate constant k = 4.8 x 10-2 min-1. However, the direct photodegradation reaction could not make the 4-t-OP mineralized. The photodegradation efficiency increased from 88% to 91.2% in 45 min irradiation period after the internal surface of SPS was sintered with TiO2 thin film as catalyst. Catalyst concentration, number of catalyst coating layers and initial concentration of 4-t-OP were proven to be the factors affecting the photocatalytic degradation performance of the SPS on aqueous 4-t-OP. The degradation mechanism was investigated and the byproducts were analyzed using total organic carbon analyzer （TOC） and LC-MS. The possible chemical structures of the products were suggested. SPS with single layer of TiO2 prepared by sintering 13.6% of TiO2 precursor was proven to be more efficient than most of previous systems for removal of 4-t-OP from aqueous phase. 28.3% of the 4-t-OP was mineralized in 45 min according to the decreased amount of TOC value.

关键词： spiral photoreactor system UV light 4-t-OP photocatalytic degradation TiO2

photocatalytic degradation of carbofuran in TiO_2 aqueous solution: Kinetics using design of experiments and mechanism by HPLC/MS/MS

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Journal of Environmental Sciences 2013年第8期25卷 1680-1686页

作者： Hai Yang Shuolin Zhou Huajie Liu Weiwei Yan Liping Yang Bing Yi College of Chemistry and Chemical Engineering Hunan Institute of Engineering College of Chemistry and Chemical Engineering Hunan Normal University South China Institute of Environmental Sciences Ministry of Environmental Protection

The photocatalytic degradation kinetics of carbofuran was optimized by central composite design based on response surface methodology for the first time. Three variables, TiO2 concentration, initial pH value and the concentration of carbofuran, were selected to determine the dependence of degradation efficiencies on independent variables. Response surface methodology modeling results indicated that the degradation efficiency of carbofuran was highly affected by the initial pH value and the concentration of carbofuran. Then nine degradation intermediates were detected by HPLC/MS/MS. The Frontier Electron Densities of carbofuran were calculated to predict the active sites on carbofuran attacked by hydroxyl radicals and photoholes. Point charges were used to elucidate the chemisorption pattern on TiO2 catalysts during the photocatalytic process. By combining the experimental results and calculation data, the photocatalytic degradation pathways of carbofuran were proposed, including the addition of hydroxyl radicals and the cleavage of the carbamate side chain.

关键词： carbofuran photocatalytic degradation central composite design kinetics mechanism

photocatalytic degradation of organic dyes with H_3PW_(12)O_(40)/TiO_2-SiO_2

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Rare Metals 2016年第10期35卷 797-803页

作者： Shui-Jin Yang Yu-Lin Xu Wen-Peng Gong Yong-Kui Huang Guo-Hong Wang Yun Yang Chuan-Qi Feng Hubei Collaborative Innovation Center for Rare Metal Chemistry College of Chemistry and Chemical EngineeringHubei Normal University College of Chemistry and Chemical Engineering Hubei University

H3PW12O40/TiO2-SiO2 was synthesized by impregnation method which significantly improved the catalytic activity under simulated natural light. The prop- erties of the samples were characterized by Fourier trans- form infrared spectra （FTIR）, X-ray powder diffraction pattern （XRD）, Scanning electron micrographs （SEM）, and Zeta potential. degradation of methyl violet was used as a probe reaction to explore the influencing factors on the photodegradation reaction. The results show that the opti- mal conditions are as follows： initial concentration of methyl violet of 10 mg·L^-1, pH of 3.0, catalyst dosage of 2.9 g·L^-1, and light irradiation time of 2.5 h. Under these conditions, the degradation rate of methyl violet is 95.4 %. The reaction on photodegradation for methyl violet can be expressed as the first-order kinetic model, and the possible mechanism for the photocatalysis under simulated natural light is suggested. After used continuously for five times, the catalyst keeps the inherent photocatalytic activity for degradation of dyes. The photodegradation of methyl orange, methyl red, naphthol green B, and methylene blue was also tested, and the degradation rate of dyes can reach 81%-100%.

关键词： Heteropoly acid TiO2 SiO2 photocatalytic degradation Organic dye

photocatalytic degradation of Chicago Sky Blue 6B and Benzopurpurin 4B using titanium dioxide thin film

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Journal of Environmental Sciences 2005年第5期17卷 869-872页

作者： Abdul K. Mohammed Katrina T. McKenzie Department of Chemistry Winston-Salem State UniversityDepartment of Chemistry North Carolina Agricultural and Technical State University 601 S. Martin Luther King Jr. Drive Winston-Salem North Carolina 27110 USA1601 E. Market Street Greensboro North Carolina 27411 USA

Aqueous solutions of azo dyes undergo degradation to form harmless intermediates and colorless products following irradiation by visible light in the presence of titanium dioxide thin films. The dyes that were studied in this work are： Chicago Sky Blue 6B and Benzopurpurin 4B. Results obtained indicated that complete mineralization of the dyes took place under the experimental conditions. There was an increase in conductivity after the complete mineralization experiments possibly indicating the formation of ions such as NO3^- and SO4^2-. Chemical oxygen demand（COD） measurements show a decrease in organic matter for both dyes following complete degradation. The effect of how changing experimental conditions such as pH, temperature and starting concentrations of dyes affected the rate of dye degradation was measured. There was an increase in the rate of disappearance of the dye color at lower pH. High concentrations of dye solutions reauired Iona dearadation time.

关键词： titanium dioxide photocatalysis photocatalytic degradation azo dyes