• Title, Summary, Keyword: Photocatalytic degradation

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Synthesis of CuO/ZnO Nanoparticles and Their Application for Photocatalytic Degradation of Lidocaine HCl by the Trial-and-error and Taguchi Methods

  • Giahi, M.;Badalpoor, N.;Habibi, S.;Taghavi, H.
    • Bulletin of the Korean Chemical Society
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    • v.34 no.7
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    • pp.2176-2182
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    • 2013
  • A novel sol-gel method was implied to prepare CuO-doped ZnO nanoparticles. XRD and SEM techniques were used to characterize the CuO-doped ZnO sample. The photocatalytic degradation of Lidocaine HCl was investigated by two methods. The degradation was studied under different conditions such as the amount of photocatalyst, pH of the system, initial concentration, presence of electron acceptor, and presence of anions. The results showed that they strongly affected the photocatalytic degradation of Lidocaine HCl. The photodegradation efficiency of drug increased with the increase of the irradiation time. After 6 h irradiation with 400-W mercury lamp, about 93% removal of Lidocaine HCl was achieved. The degree of photodegradation obtained by Taguchi method compatible with the trial-and-error method showed reliable results.

Photodegradation of Phenol over TiO2-SiO2 Catalysts Prepared by Sol-gel Method (졸-겔법으로 제조한 TiO2-SiO2촉매에서 페놀의 광분해 반응)

  • 홍성수;이만식;이근대;주창식
    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.597-603
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    • 2002
  • Photocatalytic degradation of phenol was carried out with UV-illuminated TiO$_2$-SiO$_2$ in aqueous suspension. TiO$_2$-SiO$_2$ catalysts were prepared by sol-gel method from the titanium isopropoxide and tetraethylorthosilicate at different Ti/Si ratio and some commercial TiO$_2$ catalysts were used as purchased. All catalysts were characterized by X-ray Diffraction(XRD) and BET surface area analyzer. The effect of reaction conditions, such as initial concentration of phenol, reaction temperature and catalyst weight on the photocatalytic activity was studied. In addition, TiO$_2$-SiO$_2$(49: 1) prepared by sol-gel method showed higher activity than commercial TiO$_2$catalysts on the photocatalytic degradation of phenol. The addition of SiO$_2$ into TiO$_2$hepled to increase the thermal stability of titania which suppressed the formation of anatase into rutile. The photocatalytic degradation of phenol showed pseudo-1st order reaction and the degradation rate increases with decreasing initial phenol concentration.

Photocatalytic degradation of textile dye CI Basic Yellow 28 wastewater by Degussa P25 based TiO2

  • Konecoglu, Gulhan;Safak, Toygun;Kalpakli, Yasemen;Akgun, Mesut
    • Advances in environmental research
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    • v.4 no.1
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    • pp.25-38
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    • 2015
  • Wastewaters of textile industry cause high volume colour and harmful substance pollutions. Photocatalytic degradation is a method which gives opportunity of reduction of organic pollutants such as dye containing wastewaters. In this study, photocatalytic degradation of C.I. Basic Yellow 28 (BY28) as a model dye contaminant was carried out using Degussa P25 in a photocatalytic reactor. The experiments were followed out at three different azo dye concentrations in a reactor equipped UV-A lamp (365 nm) as a light source. Azo dye removal efficiencies were examined with total organic carbon and UV-vis measurements. As a result of experiments, maximum degradation efficiency was obtained as 100% at BY28 concentration of $50mgL^{-1}$ for the reaction time of 2.5 h. The photodegradation of BY28 was described by a pseudo-first-order kinetic model modified with the langmuir-Hinshelwood mechanism. The adsorption equilibrium constant and the rate constant of the surface reaction were calculated as $K_{dye}=6.689{\cdot}10^{-2}L\;mg^{-1}$ and $k_c=0.599mg\;L^{-1}min^{-1}$, respectively.

Photocatalytic Degradation Characteristics of Organic Compound by Boron-doped TiO2 Catalysts

  • Nam, Chang-Mo
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.6
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    • pp.649-656
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    • 2010
  • Boron-doped $TiO_2$ photocatalysts were synthesized by a modified sol-gel method and their photocatalytic activities were performed and compared with those of pure synthetic and commercial $TiO_2$ catalysts under UV or visible light conditions. Pure $TiO_2$ itself exhibited very negligible photocatalytic performance under visible light conditions in the aspects of toluene decomposition reactions, although significant decomposition potential was observed as expected with UV light conditions. However, boron doping over $TiO_2$ significantly improved photocatalytic activity particularly under visible conditions, where over 95% degradation of toluene was achieved with 1wt% $B-TiO_2$ within 2 hrs. All the decomposition reactions seemed to follow pseudo first-order kinetics. The effects of boron-doping and its characteristics are further discussed through the kinetic studies and comparison of results.

Fundamental Study on the Photocatalytic Degradation of Organics in Industrial Waste Water with the Presence of Titanium Dioxide

  • Kusaka, Eishi;Izawa, Mihiro;Fukunaka, Yasuhiro;Ishii, Ryuji
    • Proceedings of the IEEK Conference
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    • pp.286-291
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    • 2001
  • As part of fundamental studies on the degradation of the organic compounds in industrial waste water, the photocatalytic degradation properties of the organic compound by means of the UV/TiO$_2$degradation process have been investigated. The test organic compound of acetic acid was chosen in this study. The testing of photo catalytic degradation were performed under various operation conditions such as TiO$_2$dosages, initial concentration of the organic, the aqueous pH's, etc. The effects of various parameters on the short time activity of the present acetic acid-UV/TiO$_2$system could be demonstrated from this investigation.

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Degradation of a Refractory Organic Contaminant by Photocatalytic Systems

  • Kim, Il-Kyu
    • Journal of the Korea Society For Power System Engineering
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    • v.18 no.6
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    • pp.133-139
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    • 2014
  • In this research, the photocatalytic degradation of benzothiophene in $TiO_2$ aqueous suspension has been studied. $TiO_2$ photocatalysts are prepared by a sol-gel method. The dominant anatase-structure on $TiO_2$ particles is observed after calcining the $TiO_2$ gel at $500^{\circ}C$ for 1hr. Photocatalysts with various transition metals (Nd, Pd and Pt) loading are tested to evaluate the effect of transition metal impurities on photodegradation. The photocatalytic degradation in most cases follows first-order kinetics. The maximum photodegradation efficiency is obtained with $TiO_2$ dosage of 0.4g/L. The photodegradation efficiency with Pt-$TiO_2$ is higher than pure $TiO_2$ powder. The optimal content value of Pt is 0.5wt.%. Also we investigate the applicability of $H_2O_2$ to increase the efficiency of the $TiO_2$ photocatalytic degradation of benzothiophene. The optimal concentration of $H_2O_2$ is 0.05. The effect of pH is investigated; we obtain the maximum photodegradation efficiency at pH 9. Hydroxy-benzothiophenes and dihydroxy-benzothiophenes are identified as reaction intermediates. It is proposed that benzothiophene is oxidized by OH radical to sequentially form hydroxyl-benzothiophenes, dihydroxybenzothiophenes, and benzothiophenedione.

Investigation of Photocatalytic Process on Removal of Natural Organic Matter in Nanofiltration Process (광촉매 공정에 의한 유기물 제거가 나노여과 공정에 미치는 영향)

  • Lee, Kew-Ho;Choi, In-Hwan;Kim, In-Chul;Min, Byoung-Ryul
    • Membrane Journal
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    • v.17 no.3
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    • pp.244-253
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    • 2007
  • This research investigated the effect of a photocatalytic reaction on nanofiltration(NF) membrane fouling by natural organic matter(NOM). The photocatalytic degradation was very effective for destruction and transformation of NOM and was carried out by titanium dioxide($TiO_2$) and $TiO_2$-immobilized bead as a photocatalyst. In order to compare their phtocatalytic properties, the photocatalytic degradation of humic acid in the presence of calcium ion was used as a model reaction. After the photocatalytic degradation the membrane fouling was dramatically decreased.

Photocatalytic Degradation of 3-Nitrophenol with ZnO Nanoparticles under UV Irradiation

  • Li, Jiulong;Ko, Weon Bae
    • Elastomers and Composites
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    • v.52 no.2
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    • pp.131-135
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    • 2017
  • Zinc nitrate hexahydrate [$Zn(NO_3){\cdot}6H_2O$] and sodium hydroxide [NaOH] were used as source reagents in the preparation of ZnO nanoparticles in an aqueous solution containing deionized water and ethanol in a ratio of 2:5 (v/v). ZnO nanoparticles were heated in an electric furnace at $700^{\circ}C$ for 2 h under an atmosphere of inert argon gas. The morphological and structural properties of the nanoparticles were characterized by scanning electron microscopy (SEM) and powder X-ray diffractometry (XRD). UV-vis spectrophotometry was used to analyze the photocatalytic degradation of 3-nitrophenol with ZnO nanoparticles as photocatalyst under ultraviolet irradiation at 254 nm. Evaluation of the kinetic of the photo-catalytic degradation of 3-nitrophenol indicated that the degradation of 3-nitrophenol with ZnO nanoparticles obeyed the pseudo-first order reaction rate model.

Photocatalytic Degradation of Atrazine and PCP using TiO2 (TiO2 광촉매를 이용한 Atrazine과 PCP의 분해)

  • Park, Jae-Hong;An, Sang-Woo;Chang, Soon-Woong
    • Journal of Korean Society on Water Environment
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    • v.20 no.6
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    • pp.577-582
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    • 2004
  • The photocatalytic degradation of atrazine and PCP, a endocrine disruptors, has been investigated over $TiO_2$ photocatalysts under ultraviolet (UV) light irradiation. The effect of operational parameters, i.e., pH, light intensity and persulphate concentration on the degradation rate of aqueous solution of atrazine and PCP has been examined. The results presented in this work demonstrate that, as pH and the light intensity increased, the photocatalytic reaction rates were enhanced. Individual use of $TiO_2$-persulphate was far more effective than using only $TiO_2$ in atrazine and PCP removal. Based on the overall experimental results, the photocatalytic oxidation of atrazine and PCP with the coated $TiO_2$ photocatalyst is found to be very effective under the operational conditions delineated in this study.

A Study on Photocatalytic Degradation Properties by Oxygen Partial Pressure for Tio2Thin Films Fabricated by DC Magnetron Sputtering (DC 마그네트론 스퍼터링법으로 제조된 Tio2 박막의 산소분압비에 따른 광분해 특성에 관한 연구)

  • Jeong, W.J.;Park, J.Y.;Park, G.C.
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.3
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    • pp.226-230
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    • 2005
  • This paper describes the photocatalytic degradation properties by oxygen partial pressure for TiO$_2$ thin films fabricated by dc magnetron reactive sputtering. And the structural, chemical, optical and photocatalytic properties were investigated at various analysis system. When TiO$_2$ thin film was made at deposition time of 120 min and Ar:O$_2$ ratio of 60:40, the best properties were obtained. That results were as follows: thickness; 360∼370 nm, gram size; 40 nm, optical energy band gap; 3.4 eV and Benzene conversion in the photocatalytic degradation; 11 %.