• 제목/요약/키워드: Photocatalytic paper

검색결과 44건 처리시간 0.027초

TiO$_2$를 이용한 메틸메르캅탄의 광촉매 분해메커니즘 (Photocatalytic Degradation Mechanism of Methyl Mercaptan using $TiO_2$)

  • 이병대;이진식;김영찬
    • 한국응용과학기술학회지
    • /
    • 제24권3호
    • /
    • pp.296-300
    • /
    • 2007
  • This paper presents applicability of photocatalytic decomposition of methyl mercaptan using $TiO_2$. A quartz reactor was used in order to elucidate reaction pathway in photocatalytic decomposition of methyl mercaptan. Experimental results showed that more than 99.9% of methyl mercaptan was decomposed within 30 minutes. It was found that the photocatalytic decomposition of methyl mercaptan followed pseudo first order and its reaction coefficient was $0.05min^{-1}$ During 30 minutes in the photocatalytic reaction, the concentration of methyl mercaptan, dimethyl disulfide, $SO_2$, $H_2SO_4$, COS, $H_2S$ were determined. These results showed that 64% of methyl mercaptan were compensated for the increase in sulfur after 30 minutes through the mineralization. The proposed main photocatalytic decomposition pathway of methyl mercaptan was methyl $mercaptan{\rightarrow}dimethyl$ $disulfide{\rightarrow}SO_2{\rightarrow}H_2SO_4$.

나노 이산화티탄 광촉매 코팅을 적용한 모르타르의 자기정화성능 평가 (Evaluation of Self-Cleaning Performance of Mortar Using Nano-Titanium Dioxide Photocatalytic Coating)

  • 양인환;전효진;이승진
    • 한국건설순환자원학회논문집
    • /
    • 제10권1호
    • /
    • pp.56-65
    • /
    • 2022
  • 본 연구에서는 시설물의 자기정화성능을 확보하기 위하여 이산화티탄 광촉매 용액을 코팅한 모르타르의 자기정화성능을 분석하였다. 광촉매 코팅 용액의 농도(1.5 %와 3.0 %), 초친수강화 용액 적용 유무 및 프라이머 용액의 사용 유무를 실험변수로 고려하였다. 광촉매 농도가 증가할수록 메틸렌블루 수용액의 색상 변화율이 증가하였으며, 이는 광촉매 농도가 증가할수록 자기정화성능이 증가하는 것을 나타낸다. 초친수성 광촉매 용액의 적용은 일반 광촉매 용액에 비해 자기정화성능을 다소 감소시킬 가능성이 있음을 나타낸다. 또한, 프라이머를 사용한 모르타르의 자기정화성능은 프라이머를 사용하지 않은 모르타르의 자기정화성능과 뚜렷한 차이를 나타내지 않는다. 한편, 낮은 농도(1.5 %)로 코팅된 모르타르에 비해 높은 농도(3.0 %)로 코팅된 모르타르 시편 표면의 코팅 균열이 미세하여 상대적으로 큰 광촉매 반응면적을 확보하고 자기정화성능 증가에 유리한 영향을 미친 것으로 판단된다.

A Kinetic Study on the Photocatalytic Degradation of Gas-Phase VOCs Using TiO$_2$ photocatalyst

  • Kim, Sang-Bum;Jo, Young-Min;Hong, Sung-Chang
    • Journal of Korean Society for Atmospheric Environment
    • /
    • 제17권E3호
    • /
    • pp.117-124
    • /
    • 2001
  • The present paper examined the kinetics of photocatalytic degradation of volatile organic compounds (VOCs) including gaseous trichloroethylene (TCE) and acetone. In this study, we examined the effects of the initial concentration of VOCs and the light intensity of ultra-violet (UV). A batch photo-reactor was specifically designed for this work. The photocatalytic degradation rate increased with the initial concentration of VOCs but remained almost constant beyond a certain concentration. It matched well with the Langmuir-Hinshelwood (L-H) kinetic model. When the effect of light intensity was concerned, it was found that photocatalytic degradation occurs in two regimes with respect to light intensity.

  • PDF

Photocatalytic activities and surface properties of e-beam treated carbon paper deposited $TiO_2$ using Atomic Layer Deposition (ALD)

  • Kim, Myoung-Joo;Seo, Hyun-Ook;Luo, Yuan;Kim, Kwang-Dae;Kim, Young-Dok
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
    • /
    • pp.345-345
    • /
    • 2010
  • Thin film of $TiO_2$ deposited on carbon paper was fabricated by atomic layer deposition (ALD) using titanium isopropoxide (TTIP) and $H_2O$ as precursors. In this work, the photocatalytic activities of $TiO_2$ films with and without e-beam treatment were compared. The samples were treated by e-beam using e-beam energy of 1MeV and exposure range between 5 and 15kGy. The photocatalytic activity was evaluated by the photocatalytic degradation of methyleneblue (MB) under UV irradiation (365nm) at room temperature using an UV-vis spectroscopy. The surface properties were characterized by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The sample treated by the low radiation dose has more catalytic activity than other ones. SEM images show that the high radiation dose caused the $TiO_2$ to aggregation on carbon paper. Due to the aggregation of $TiO_2$, the partially exposed carbon paper was oxidized.

  • PDF

이산화티타늄-발광체 복합소재 제조 및 가시광선 광촉매 반응 (Preparation of the Titanium Dioxide-Phosphor Composite and its Photocatalytic Reaction under Visible Light)

  • 박진우;김정식
    • 한국세라믹학회지
    • /
    • 제45권11호
    • /
    • pp.688-693
    • /
    • 2008
  • This paper presents a study on the photocatalytic reaction about the composite particles of $TiO_2$-coated phosphors under visible light irradiation. Nanocrystalline titanium dioxide layers were directly coated on the alkaline earth aluminate phosphor, $CaAl_2O_4:Eu^{2+},\;Nd^{3+}$ particles by an sol-gel processing method. The photocatalytic reaction was analyzed with the degradation of methylene blue (MB) aqueous solution under UV and visible light irradiations. $TiO_2$-coated phosphor powders showed different photocatalytic mechanism, compared with pure $TiO_2$ (P-25, Degussa). Under UV-irradiation, $TiO_2$-coated phosphor powders showed slow photocatalytic reactivity in the early stage and fast in the latter, compared with that of pure $TiO_2$. However, $TiO_2$-coated phosphor powders showed much faster photocatalytic reactivity than that of pure $TiO_2$ under visible irradiation. In addition, the characterizations of the $TiO_2$-coated phosphor powders were conducted by a X-ray diffractometer (XRD), transmission electron microscope (TEM), and energy dispersive spectroscopy (EDS).

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

  • 정운조;박중윤;박계춘
    • 한국전기전자재료학회논문지
    • /
    • 제18권3호
    • /
    • pp.226-230
    • /
    • 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 %.

VOC흡착 및 산화분해 특성을 갖는 광촉매종이의 제조 및 특성 평가 (Preparation and Characterization of Photocatalytic Paper for VOCs Adsorption and Oxidation Decomposition)

  • 유윤종;김흥수;전상호;장건익
    • 한국세라믹학회지
    • /
    • 제42권1호
    • /
    • pp.56-61
    • /
    • 2005
  • 아나타제 $TiO_{2}$, 활성탄, 세라믹섬유를 포함하는 VOC 흡착과 광산화분해 특성을 동시에 갖는 내구성이 우수한 광촉매 종이를 제조하여 그 특성을 분석하였다. 광촉매 종이 제조용 슬러리 내에 함유되어 있는 $TiO_{2}$를 활성탄 및 세라믹섬유 표면에 선택적으로 결합시키기 위한 PDADMAC의 적정농도범위는 $10{\~}15ppm$이었으며, 제지방법에 의해 만들어진 광촉매 종이는 두께 0.4mm, 평량 $380g/m^{2}$을 나타내었다. 제조된 광촉매 종이는 활성탄에 의한 흡착과 $TiO_{2}$에 의한 광산화 분해 반응이 동시에 진행되어 이들 두 반응이 각각 단독으로 진행되는 VOC 제거용 소재에 비하여 아세트알에히드의 제거속도를 크게 증가시켰다. 또한 세라믹섬유-$TiO_{2}$, 활성탄-$TiO_{2}$의 선택적인 결합은 UV 조사시 $TiO_{2}$에 의한 기지내 유기물의 분해를 방지하여 내구성을 개선하는데 효과적이었다.

The Effect of Photocatalysis using $TiO_2$ and UV for COD Degradation of Wastewater in Linerboard Mill

  • Kang, Kwang-Ho;Kim, Hyoung-Jin
    • 펄프종이기술
    • /
    • 제40권5호
    • /
    • pp.53-59
    • /
    • 2008
  • This study was carried out to investigate the effect of photocatalysis using $TiO_2$ and UV applied for the COD reduction of wastewater in linerboard mill. Trials were done to obtain the optimum addition amounts of $TiO_2$ and $H_2O_2$ to the wastewater and find an appropriate pH condition for photocatalysis on $TiO_2$ for degrading COD. The photocatalytic reaction was applied to the wastewater collected after secondary activated sludge treatment in WWTP of linerboard mill. The optimum application of photocatalysis reaction was obtained under the addition conditions of 2 g/L of $TiO_2$ and 200 mg/L of $H_2O_2$ at pH 3.0, respectively. The removal efficiency of $SCOD_{Cr}$ by photocatalytic treatment was 86.4 % and higher than Fenton treatment in which removal efficiency was 67.4 %. It was concluded that the photocatalytic process using $TiO_2$ and UV could be applied to the wastewater treatment in linerboard mill and also to the dramatic drop-off in NBDCOD load from wastewater of tertiary treatment in WWTP.

대기압 마이크로웨이브 플라즈마를 이용한 다양한 크기의 ZnO tetrapod 합성 및 광촉매 특성 평가 (Synthesis of size-controlled ZnO tetrapods sizes using atmospheric microwave plasma system and evaluation of its photocatalytic property)

  • 허성규;정구환
    • 한국표면공학회지
    • /
    • 제54권6호
    • /
    • pp.340-347
    • /
    • 2021
  • Among various metal oxide semiconductors, ZnO has an excellent electrical, optical properties with a wide bandgap of 3.3 eV. It can be applied as a photocatalytic material due to its high absorption rate along with physical and chemical stability to UV light. In addition, it is important to control the morphology of ZnO because the size and shape of the ZnO make difference in physical properties. In this paper, we demonstrate synthesis of size-controlled ZnO tetrapods using an atmospheric pressure plasma system. A micro-sized Zn spherical powder was continuously introduced in the plume of the atmospheric plasma jet ignited with mixture of oxygen and nitrogen. The effect of plasma power and collection sites on ZnO nanostructure was investigated. After the plasma discharge for 10 min, the produced materials deposited inside the 60-cm-long quartz tube were obtained with respect to the distance from the plume. According to the SEM analysis, all the synthesized nanoparticles were found to be ZnO tetrapods ranging from 100 to 600-nm-diameter depending on both applied power and collection site. The photocatalytic efficiency was evaluated by color change of methylene blue solution using UV-Vis spectroscopy. The photocatalytic activity increased with the increase of (101) and (100) plane in ZnO tetrapods, which is caused by enhanced chemical effects of plasma process.

Preparation of MWCNT/TiO2 Composites by Using MWCNTs and Titanium(IV) Alkoxide Precursors in Benzene and their Photocatalytic Effect and Bactericidal Activity

  • Oh, Won-Chun;Zhang, Feng-Jun;Chen, Ming-Liang
    • Bulletin of the Korean Chemical Society
    • /
    • 제30권11호
    • /
    • pp.2637-2642
    • /
    • 2009
  • In this present paper, we prepared $MWCNT/TiO_2$ composites by using pre-oxidized multi-walled carbon nanotubes (MWCNTs) with different titanium alkoxide precursors in benzene solvent. The composites were comprehensively characterized by BET surface area, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and UV-Vis absorption spectroscopy. The photoactivity of the prepared materials, under UV irradiation, was tested using methylene blue (MB) in aqueous solution. Finally, according to the results of MB removal experiment, it can be considered that the MB degradation infect mainly caused by photocatalytic effect of $TiO_2$. Furthermore, the bactericidal test of the composites was also determined. It was indicated that $MWCNT/TiO_2$ composites with sunlight had greater effectiveness for B. cereus, S. aureus and E. coli than any other experimental conditions.