• Title, Summary, Keyword: Photocatalytic degradation

Search Result 403, Processing Time 0.041 seconds

Photocatalytic Degradation of Pheonol in UV/TiO2 Honeycomb Reactor (UV/TiO2 허니컴 반응기에서 페놀의 광산화 반응)

  • Han, Po-Keun;Park, Sang-Eun;Lee, Sang-Wha
    • Applied Chemistry for Engineering
    • /
    • v.17 no.1
    • /
    • pp.100-105
    • /
    • 2006
  • The photocatalytic activity of phenol degradation was investigated with the variation of operating parameters in $UV/TiO_2$ honeycomb reactor. In the comparison of phenol degradation rates among various $TiO_2$, Ishihara (STS-02)-coated honeycomb exhibited a slightly higher photocatalytic activity than Degussa P25-coated honeycomb. On the other hand, honeycomb coated by alcohol-mixed $TiO_2$ (N Co.) did not exhibit any photocatalytic activity on phenol degradation. With the increase of Degussa P25 coating amounts, the honeycomb reactor exhibited the gradual increase of phenol degradation rates. The degradation rate of phenol over $UV/TiO_2$ (Degussa P25) honeycomb reactor was asymptotically increased up to 500 mL/min, subsequently followed by a slight decrease as the recirculation rate (100~700 mL/min) was increased. UV absorption at 269 nm was high due to partial degradation of phenol at initial reaction time because the honeycomb surface was pre-adsorbed by phenol prior to UV irradiation.

Synergistic Effect on the Photocatalytic Degradation of 2-Chlorophenol Using $TiO_2$Thin Films Doped with Some Transition Metals in Water

  • Jeong, O Jin
    • Bulletin of the Korean Chemical Society
    • /
    • v.22 no.11
    • /
    • pp.1183-1191
    • /
    • 2001
  • The metallorganic chemical vapor deposition (MOCVD) method has been used to prepare TiO2 thin films for the degradation of hazardous organic compounds, such as 2-chlorophenol (2-CP). The effect of supporting materials and metal doping on the photocatalytic activity of TiO2 thin films also has been studied. TiO2 thin films were coated onto various supporting materials, including stainless steel cloth(SS), quartz glass tube (QGT), and silica gel (SG). Transition metals, such as Pd(II), Pt(IV), Nd(III) and Fe(III), were doped onto TiO2 thin film. The results indicate that Nd(Ⅲ) doping improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 ${\mu}m)$ appears to be the best support. An optimal amount of doping material at 1.0 percent (w/w) of TiO2-substrate thin film gives the best photodegration of 2-CP.

  • PDF

UV Light Induced Photocatalytic Degradation of Cyanides in Aqueous Solution over Modified $TiO_2$

  • Kim, Hyeong Ju;Kim, Jae Hyeon;Lee, Cheong Hak;Hyeon, Taek Hwan;Choe, Won Yong;Lee, Ho In
    • Bulletin of the Korean Chemical Society
    • /
    • v.22 no.12
    • /
    • pp.1371-1374
    • /
    • 2001
  • Metal doping was adopted to modify TiO2 (P-25) and enhance the photocatalytic degradation of harmful cyanides in aqueous solution. Ni, Cu, Co, and Ag doped TiO2 were found to be active photocatalysts for UV light induced degradation of aqueous cyanides generating cyanate, nitrate and ammonia as main nitrogen-containing products. The photoactivity of Ni doped TiO2 was greatly affected by the state of Ni, that is, the crystal size and the degree of reduction of Ni. The modification effects of some mixed oxides, that is, Ni-Cu/TiO2 were also studied. The activity of Ni-Cu/TiO2 for any ratio of Cu/Ni was higher than that of Ni- or Cu-doped TiO2, and the catalyst at the Cu/Ni ratio of 0.3 showed the highest activity for cyanide conversion.

  • PDF

PHOTOCATALYTIC DEGRADATION OF 2-CHLOROPHENOL USING TiO₂THIN FILMS PREPARED BY CHEMICAL VAPOR DEPOSITION AND ION BEAM SPUTTERING METHOD

  • Jung, Oh-Jin;Kim, Sam-Hyeok;Jo, Ji-Eun;Hwang, Chul-Ho
    • Environmental Engineering Research
    • /
    • v.7 no.4
    • /
    • pp.227-237
    • /
    • 2002
  • Chemical vapor deposition (CVD), ion beam sputtering (IBS) and sol-gel method were used to prepare TiO$_2$ thin films for degradation of hazardous organic compounds exemplified by 2-chlorophenol (2-CP). The influence of supporting materials and coating methods on the photocatalytic activity of the TiO$_2$ thin films were also studied. TiO$_2$ thin films were coated onto various supporting materials including steel cloth (SS), copper cloth, quartz glass tube (QGT), and silica gel (SG). Results indicate that SS (37 μm)- TiO$_2$ thin film prepared by IBS method improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 μm) is found to be the best support.

Application of Photocatalytic Reaction Using TiO2 Thin Film (TiO2 박막을 이용한 광촉매반응의 응용)

  • Kim, Yeong-Kwan;Kim, Sung-Ho;Kim, Dong-Hyun
    • Journal of Industrial Technology
    • /
    • v.17
    • /
    • pp.249-254
    • /
    • 1997
  • Photocatalytic reaction using $TiO_2$ thin film was applied for the inactivation of coliform bacteria and the degradation of formic acid. UV processes coupled with and without $TiO_2$ were tested for the river water samples. It took 5 and 15 minutes, respectively, to obtain 99% destruction of coliform bacteria in the total coliform test, which demonstrated the effectiveness of the photocatalytic reaction. Complete degradation of formic acid determined by TOC analysis was observed in 20 minutes by ozone/photocatalysis, while formic acid was degraded as little as about 20% during the first 100 minutes by ozone treatment alone. When ozone was supplied to the $TiO_2/UV$ system, however, it provided a synergetic effect for the degradation of formic acid.

  • PDF

Removal of Bisphenol-A using Rotating Photocatalytic Oxidation Drum Reactor (RPODR)

  • Son, Hee-Jong;Jung, Chul-Woo;Kim, Seung-Hyun
    • Environmental Engineering Research
    • /
    • v.13 no.4
    • /
    • pp.197-202
    • /
    • 2008
  • This study evaluated the photocatalytic oxidation of BPA using the RPOD reactor under various conditions. This study found that the RPOD was effective for BPA degradation. It could reduce 1 mg/L of BPA by half within 5 min under the optimum conditions. According to the study results, $TiO_2$ coating was important for the BPA oxidation. As the coating thickness increased, the removal efficiency improved. The light source, the light intensity and the drum rotating speed were important for the oxidation. The UV light was more effective for the BPA degradation than the visible light. The removal efficiency improved with increasing intensity. As the drum speed increased, the removal efficiency improved. The maximum speed was 240 rpm in this study. Addition of air and nitrogen was not beneficial for the BPA degradation in this study probably due to enough oxygen in the water.

Preparation of Nanosized Palladium-Graphene Composites and Photocatalytic Degradation of Various Organic Dyes

  • Kim, Jae Jin;Ko, Weon Bae
    • Elastomers and Composites
    • /
    • v.51 no.1
    • /
    • pp.10-16
    • /
    • 2016
  • Nanosized palladium particles were synthesized using palladium(II) chloride, trisodium citrate dihydrate, and sodium borohydride under stirring condition. Nanosized palladium-graphene composites were prepared from palladium nanoparticles, and graphene was enclosed with polyallylamine under stirring condition for 1 h followed by ultrasonication for 3 h. Nanosized palladium-graphene composites were heated in an electric furnace at $700^{\circ}C$ for 2 h and characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. UV-vis spectrophotometry was used to evaluate the nanosized palladium-graphene composites as a catalyst in the photocatalytic degradation of various organic dyes such as methylene blue, methyl orange, rhodamine B, and brilliant green under ultraviolet light at 254 nm.

Preparation of Fe-AC/$TiO_2$ composites and pH dependence of their Photocatalytic activity for methylene blue

  • Meng, Ze-Da;Zhang, Kan;Oh, Won-Chun
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.19 no.5
    • /
    • pp.268-276
    • /
    • 2009
  • In this study, activated carbon (AC) was treated with ferric ion by a sol-gel method. The compound (Fe-AC) was employed for the preparation of Fe-activated carbon/$TiO_2$, (Fe-AC/$TiO_2$) composites. The prepared Fe-AC/$TiO_2$ composites were characterized with surface properties, structural crystallinity, elemental identification and photocatalytic activity. The SEM results showed that ferric compounds and titanium dioxide were fixed onto the AC surfaces. The XRD results showed that Fe-AC/$TiO_2$ composites mostly contained anatase phase. EDX showed the presence of C, O, and Ti with Fe peaks in all samples. Its photocatalytic degradation effect was evaluated with the degradation behavior of the methylene blue (MB) solution. MB degradation could be attributed to the synergetic effects of adsorption, photo-degradation of $TiO_2$ and photo-Fenton of Fe component. The degradation rate for this photocatalysis was evaluated as a function of the concentration of the dye, the amount of $TiO_2$ and the pH. Photocataytic activity is good at activity pH.

Optimization of photo-catalytic degradation of oil refinery wastewater using Box-Behnken design

  • Tetteh, Emmanuel Kweinor;Naidoo, Dushen Bisetty;Rathilal, Sudesh
    • Environmental Engineering Research
    • /
    • v.24 no.4
    • /
    • pp.711-717
    • /
    • 2019
  • The application of advanced oxidation for the treatment of oil refinery wastewater under UV radiation by using nanoparticles of titanium dioxide was investigated. Synthetic wastewater prepared from phenol crystals; Power Glide SAE40 motor vehicle oil and water was used. Response surface methodology (RSM) based on the Box-Behnken design was employed to design the experimental runs, optimize and study the interaction effects of the operating parameters including catalyst concentration, run time and airflow rate to maximize the degradation of oil (SOG) and phenol. The analysis of variance and the response models developed were used to evaluate the data obtained at a 95% confidence level. The use of the RSM demonstrated the graphical relationship that exists between individual factors and their interactive effects on the response, as compared to the one factor at time approach. The obtained optimum conditions of photocatalytic degradation are the catalyst concentration of 2 g/L, the run time of 30 min and the airflow rate of 1.04 L/min. Under the optimum conditions, a 68% desirability performance was obtained, representing 81% and 66% of SOG and phenol degradability, respectively. Thus, the hydrocarbon oils were readily degradable, while the phenols were more resistant to photocatalytic degradation.

Facile and Selective Synthesis of ZnO Hollow or Crumpled Spheres and Their Photocatalytic Degradation Activities

  • Choi, Yomin;Lee, Young-In
    • Journal of the Korean Ceramic Society
    • /
    • v.55 no.3
    • /
    • pp.261-266
    • /
    • 2018
  • Hollow or bumpy ZnO structures with micrometer-size features have been investigated as photocatalysts for water purification due to their high surface area available for reaction with harmful organic molecules and relatively large size for easy separation after finishing the photocatalytic reaction. In this study, selective synthesis of ZnO hollow or crumpled microspheres was performed using a simple and versatile ultrasonic spray pyrolysis process with various zinc precursors. The morphologies, phases, specific surface areas, and optical properties of the microspheres were characterized using X-ray diffraction, scanning electronic microscopy, nitrogen adsorption-desorption isotherms, and UV-vis spectroscopy. In addition, the mechanism underlying the formation of different morphologies and their photocatalytic activities were systematically investigated.