• 산업기술연구
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• 제22권B호
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• pp.117-124
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• 2002

We prepared the nano-sized $TiO_2$ particles by the diffusion flame reactor and investigated the effects of several process variables on the generation and transport properties of $TiO_2$ particle. As the length from the tip of diffusion flame reactor increases, the size of $TiO_2$ particle increases by the coagulation between particles. The structure of $TiO_2$ particles prepared is almost found to be anatase. It was found that the $TiO_2$ particle size depends more largely on the change of reactor temperature than on the change of inlet $TiCl_4$ concentration. By the photo-degradation experiment of phenol and toluene with the prepared $TiO_2$ particles, we found that the photo-degradation efficiencies of phenol and toluene change, depending on the process variables such as size of $TiO_2$ photocatlysts, concentration of phenol or toluene. Degradation efficiencies of phenol and toluene was above 90% in our experiments in 60 minutes.

• 산업기술연구
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• 제21권A호
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• pp.273-278
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• 2001

In this study, we prepared nano-sized $TiO_2$ particles for various process variables by the diffusion flame reactor and we collected $TiO_2$ particles by thermophoresis. It is found that the size of $TiO_2$ particles increases, as the flame temperature or the inlet $TiCl_4$ concentration increase or the total gas flow rate decreases. We investigated the photo-degradation of phenol wish the prepared $TiO_2$ particles. We found the optimum amounts of $TiO_2$ photocatalysts for our experimental apparatus and investigated the photo-degradation efficiencies of phenol, changing the process variables such as size of $TiO_2$ photocatlysts, phase ratio of rutile/anatase, concentration of phenol, input ratio of $O_2$. Degradation efficiencies of phenol were almost 95% in 15 minutes for the standard conditions of our experiments.

• 공업화학
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• 제17권1호
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• pp.100-105
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• 2006

$UV/TiO_2$ 허니컴 광촉매가 고정된 반응기에서 여러 운전 변수에 따른 페놀의 분해반응을 고찰하였다. 광촉매의 종류에 따른 페놀의 분해능을 비교한 결과, 이시하라사 STS-02로 코팅한 허니컴 광촉매는 데구사 P25에 비해 약간 높은 광산화 활성을 나타내 주었다. 반면에 국내 N사의 광촉매로 코팅한 허니컴의 경우에는 페놀의 광분해 효과가 거의 나타나지 않았다. 허니컴 광촉매는 데구사 P25의 코팅량이 증가함에 따라 페놀의 광산화 반응속도가 증가하는 경향을 나타내주었다. 데구사 P25로 코팅된 허니컴 반응기의 경우에 원수의 유량이 증가함에 따라 페놀의 광산화 속도가 지속적으로 증가하다가 500 mL/min 이상의 유속에서는 감소하는 경향을 나타내었다. 광촉매 표면이 페놀에 의해 미리 흡착된 경우에는 초기 반응시간에 자외선 조사에 의한 페놀의 부분산화 반응이 일어나 오히려 269 nm에서 페놀의 흡광도가 상승하는 결과를 나타내 주었다.

• 한국환경과학회지
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• 제11권6호
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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.

• 산업기술연구
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• 제24권B호
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• pp.133-138
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• 2004

The photodegradation of phenol and toluene with the $TiO_2$-coated polyethylene (PE) particles were investigated in the slurry type photocatalytic reactor, changing the $TiO_2$ particle sizes, initial phenol and toluene concentrations, and the oxygen flow rate. The nano-sized $TiO_2$ photocatalyst particles were prepared by the diffusion flame reactor and they were coated onto PE particles by using the hybridization system for the efficient recollection of $TiO_2$-coated particles after photodegradation experiments. The degradation efficiencies of phenol and toluene with the $TiO_2$-coated PE particles were more than 90% after photodegradation of 80 minutes for most cases. The efficiencies of photodegradation with the $TiO_2$-coated PE particles were found to be lower than those by the pure $TiO_2$ particles by 50%, because of the decrease in specific surface area of $TiO_2$ particles in PE particles.