• Electronic Materials Letters
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• 제14권6호
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• pp.739-748
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• 2018

ZnS nanowalls, microspheres and rice-shaped nanoparticles have been successfully grown on graphene oxide (GO) sheets by the hydrothermal method. The morphologies, structures, chemical compositions and optical properties of the as-synthesized GO/ZnS have been characterized by X-ray power diffraction, energy dispersive spectrometer, scanning electron microscope, Raman spectra, photoluminescence spectroscopy and ultraviolet-visible absorption spectroscopy. It was found that the concentration of CTAB and the reaction temperature were important in the formation of GO/ZnS microstructures. The photocatalytic activity of the as-synthesized GO/ZnS was investigated through the photocatalytic degradation of textile dyeing waste. Results showed that the catalytic activity of the GO/ZnS porous spheres to methyl orange and methylene blue is higher than those of other samples. The degradation rates of methyl orange and methylene blue by porous spheres in 50 min were 97.6 and 97.1%, respectively. This is mainly attributed to the large specific surface area of GO/ZnS porous spheres and high separation efficiency between photogenerated electron and hole pairs.

• Journal of the Korean Wood Science and Technology
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• 제32권3호
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• pp.79-87
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• 2004

The objectives of this study were to select superior fungus for lignin degradation and to decolor dyes by selected fungus. Ligninolytic fungi were screened and isolated from decayed woods. Ten ligninolytic fungi were selected by ligninolytic enzyme activity on the PDA media containing rhemazol brilliant blue R, guaiacol and gallic acid. Their lignin degradation abilities were tested on the extractive-free wood powder of Quercus acutissima and Pinus densiflora. As a result, 8J-28 was selected as superior fungus for lignin degradation. Also, decolorization abilities of dyes were examined by shaking and static culture. And congo red, crystal violet, poly R-478, methylene blue used to investigate decolorization abilities of dyes. As a result, 8J-28 showed over 90% in decolorization of congo red, crystal violet, poly R-478.

• 유기물자원화
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• 제25권3호
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• pp.5-12
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• 2017

촉매오존화에 의한 메틸렌 블루(MB) 제거특성과 그에 미치는 운전변수의 영향을 관찰하기 위해 회분식 실험을 수행하였다. 촉매오존화에서 오존 분해반응의 촉매로 작용하는 활성탄의 투입량이 증가함에 따라 MB 및 TOC 제거속도가 증가하는 것으로 나타났다. 반응기로 공급되는 가스상 오존의 농도가 증가함에 따라 물질전달이 크게 일어나므로 MB 제거속도를 증가시키는 것으로 나타났다. 촉매오존화에서 오존의 분해에 의해 생성된 $OH{\cdot}$에 의해 MB의 분해가 일어나므로 오존화에 비해 MB의 제거속도가 빠를 뿐 아니라 훨씬 높은 TOC 제거율을 기대할 수 있는 것으로 나타났다. 촉매오존화에서 오염물질 처리는 pH의 변화에 큰 영향을 받지 않는 것으로 나타나 현장 적용시에 있을 수 있는 유입수의 변동에 대한 적용성이 높은 것으로 나타났다. 이러한 결과는 촉매오존화가 섬유산업에서 발생하는 난분해성 폐수를 처리하기 위한 효과적인 대안이 될 수 있음을 보여준다.

• 공업화학
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• 제29권1호
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• pp.117-121
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• 2018

하폐수 고도산화처리(AOP, advanced oxidation process) 중 하나인 펜톤산화법과 전기화학적 방법을 결합한 전기펜톤산화법의 cathode에 stainless steel mesh (SUS mesh)를 적용하였다. 난분해성 물질인 염료 methylene blue (MB) 용액에 대해서, SUS mesh의 표면 처리 및 산화철 코팅 여부에 따라 전기펜톤산화 처리의 효율이 어떻게 달라지는지를 비교, 분석하였다. MB분해 반응의 효율 비교를 통해 mesh 표면에 코팅된 산화철의 양이 많을수록 전극의 촉매 특성이 높아짐을 확인하였고, 이는 전극표면에서 in situ로 발생하는 과산화수소의 발생량이 높아지는 것과 연관이 있었다. 전류-전위 순환법(CV)을 통해 개발된 전극의 전기화학적 특성을 평가해 본 결과, mesh 표면에 코팅된 산화철의 양이 많을수록 전기화학적 산화-환원 특성 또한 개선되었고, 이것이 우수한 전기펜톤산화 전극으로서의 성능과 밀접한 관계가 있음을 확인하였다.

• 한국분말재료학회지
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• 제26권1호
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• pp.40-44
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• 2019

Tungsten trioxide ($WO_3$) is a promising candidate as a photocatalyst because of its outstanding electrical and optical properties. In this study, we prepare $WO_3$ thin films by electrodeposition and characterize the photocatalytic degradation of methylene blue using these films. Depending on the voltage conditions (static and pulse), compact and porous $WO_3$ films are fabricated on a transparent ITO/glass substrate. The morphology and crystal structure of electrodeposited $WO_3$ thin films are investigated by scanning electron microscopy, atomic force microscopy, and X-ray diffraction. An application of static voltage during electrodeposition yields a compact layer of $WO_3$, whereas a highly porous morphology with nanoflakes is produced by a pulse voltage process. Compared to the compact film, the porous $WO_3$ thin film shows better photocatalytic activities. Furthermore, a much higher reaction rate of degradation of methylene blue can be achieved after post-annealing of $WO_3$ thin films.

• 대한화학회지
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• 제66권3호
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• pp.251-255
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• 2022

• 대한환경공학회지
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• 제35권9호
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• pp.636-642
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• 2013

광촉매인 나노크기의 산화아연(ZnO)과 흡착기능의 지지체인 Laponite, 결합제인 poly vinyl alcohol (PVA)를 혼합하여 붕산(boric acid)과 가교반응(crosslinking)을 통해 흡착과 광분해가 동시에 발생하며 회수가 불필요한 nano-ZnO/Laponite/PVA (ZLP) 광촉매 흡착볼을 개발하였다. ZLP 광촉매 흡착볼 제작을 위한 최적의 배합비는 Nano-ZnO:Laponite:PVA:deionized water의 구성비가 3:1:1:16 (by weight)으로 도출되었으며, PVA가 붕산과의 가교결합을 통해서 다층의 망(mesh network)과 막(film)을 형성하여 Laponite의 팽윤과 ZnO의 탈리 현상을 억제하는 것으로 사료된다. 수중안정성을 개선하고 비표면적을 높이기 위한 최적의 건조방법은 microwave를 활용하는 방법이며, SEM과 TEM의 분석을 통해 다양한 크기(55~500 ${\mu}m$)의 공극(pore)이 분포하며 ZnO의 균질한 분포를 확인할 수가 있었다. 메틸렌블루 광분해 특성은 반응 초기(40분)에는 Laponite와 메틸렌블루의 이온결합에 따른 흡착제거가 주요 제거 기작이며, 메틸렌블루의 흡착이 포화상태에 도달 후 광분해를 통한 제거가 발생함을 확인하여 흡착과 광분해가 동시에 발생하여 수중에 용해된 메틸렌 블루를 효과적으로 제거할 수 있음을 확인하였다. 본 연구를 통해 짧은 시간에 흡착과 광분해가 동시에 진행되어 난분해성 오염물질을 효과적으로 제거하는 광촉매 흡착볼의 제작이 가능하며, 나노물질의 탈리로 인해 발생하는 환경 및 수용체에 미치는 위해성도 최소화 할 수 있을 것으로 판단된다.

• 한국세라믹학회지
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• 제47권3호
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• pp.210-215
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• 2010

In this study, an expanded graphite-titanium oxide composite is developed from expanded graphite (EG) and titanium n-butoxide (TNB). EG is synthesized by chemical intercalation of natural graphite (NG) and rapid expansion at high temperature. TNB is used as the titanium source. The performances of the prepared EG-$TiO_2$ composite are characterized by BET surface area measurements, scan electron microscope (SEM), X-ray diffraction patterns (XRD) and energy dispersive X-ray analysis (EDX). The catalytic activities of the EG-$TiO_2$ composite are investigated by analysis of the degradation of methylene blue (MB) in aqueous solution under irradiation of UV light. Compared with the pristine $TiO_2$ and activity carbon-$TiO_2$ (AC-$TiO_2$) composite, the EG-$TiO_2$ composite shows very high efficiency against MB solution, and the EG could improve the photocatalytic effect of $TiO_2$ in the MB degradation reaction under the irradiation of UV light.

• 한국세라믹학회지
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• 제45권11호
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• pp.651-657
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• 2008

In this study, CNT/$TiO_2$ composites were prepared using surface modified Multiwall carbon nanotube (MWCNT) and titanium n-butoxide (TNB) with benzene. The composites were characterized by nitrogen adsorption isotherms, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), FT-IR spectra, and UV-vis absorption spectroscopy. The UV radiation induced photoactivity of the CNT/$TiO_2$ composites was tested using a fixed concentration of methylene blue (MB, $C_{16}H_{18}N_3S{\cdot}Cl{\cdot}3H_2O$) in an aqueous solution. Finally, it can be considered that the MB removal effect of the CNT/$TiO_2$ composites is not only due to the adsorption effect of MWCNT and photocatalytic degradation of $TiO_2$, but also to electron transfer between MWCNT and $TiO_2$.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.243-247
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• 2012

Photocatalysis has been applied to decompose the waste and toxic materials produced in daily life and in the global environment. Pure $TiO_2$ (Zn-$TiO_2$-0) and Zn-doped $TiO_2$ (Zn-$TiO_2$-x, x = 3-10 mol %) samples were synthesized using a novel sol-gel and ammonia-evaporation method. The Zn-doped $TiO_2$ samples showed high photocatalytic activity for the degradation of methylene blue (MB). The physicochemical properties of the samples were investigated using XRD, SEM, ICP, DLS and BET methods. In addition, the most important measurement of photocatalytic ability was investigated by a UV-vis spectrophotometer. The effects of the mol % of zinc ion doping in $TiO_2$ on photocatalytic activity were studied. Among the mol % Zn ions investigated, the Zn-$TiO_2$-9 sample showed the highest photoreactivity. This sample removed 91.4% of the MB after 4 h, while the pure $TiO_2$ only removed 46.4% of the MB.