• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.650-653
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• 2007

$SnO_2$-doped $TiO_2$ powder was obtained from tin (IV) bis(acetylacetonate) dichloride and titanium diisopropoxide bis(acetylacetonate) with quinacridone as the dye sensitizer molecule. The structural changes of the reaction mixture were monitored by fourier transform infrared (FT-IR) spectroscopy. The morphology and microstructure of gel powder were studied by field-emission scanning electron microscopy (FE-SEM) and X-ray diffractometry (XRD). The photocatalytic activity of these powders with the anatase structure was investigated by using indigo carmine solution as a test dye

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.7-10
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• 2005

[ $TiO_{2}-ZrO_{2}$ ] powders were successfully synthesized by the sol-gel process using titanium iso-propoxide as a precursor. The amorphous $TiO_{2}$ particles, 70 nm in size, homogenously adhered to the surface of $ZrO_{2}$ the powders. After calcination at $450^{circ}C$, most of the $TiO_{2}$ powders appeared as an anatase type, whereas they changed to a rutile phase at $750^{circ}C$. For comparison of photocata­lytic activity, $TiO_{2}-ZrO_{2}$ nano-sized powders calcined at $450^{circ}C,\;600^{circ}C,\;and\;750^{circ}C$ were used. In the $TiO_{2}-20wt\%$ $ZrO_{2}$ powders cal­cined at $450^{circ}C$, there was excellent removal efficiency of Methyl Orange (MO). For the calcination temperature increased, $TiO_{2}­ZrO_{2}$ nano-sized powders increased $ZrO_{2}$ contents showed the good photoactivity for the photooxidation of MO.

• Journal of the Korean Ceramic Society
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• v.45 no.11
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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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• v.33 no.7
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• pp.2133-2139
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• 2012

A new system using $TiO_2$ (nano-sized, band-gap 3.14 eV)-impregnated spherical ZnS (micro-sized, band-gap 2.73 eV) nano/micro-composites (Ti 0.001, 0.005, 0.01, and 0.05 mol %/ZnS) was developed to enhance the production of hydrogen from methanol/water splitting. The ZnS particles in a spherical morphology with a diameter of about 2-4 mm which can absorb around 455 nm were prepared by hydrothermal method. This material was used as a photocatalyst with loading by nano-sized $TiO_2$ (20-30 nm) for hydrogen production. The evolution of $H_2$ from methanol/water (1:1) photo splitting over the $TiO_2$/ZnS composite in the liquid system was enhanced, compared with that over pure $TiO_2$ and ZnS. In particular, 1.2 mmol of $H_2$ gas was produced after 12 h when 0.005 mol % $TiO_2$/ZnS nano/micro-composite was used. On the basis of cyclic voltammeter (CV) and UV-visible spectrums results, the high photoactivity was attributed to the larger band gap and the lower LUMO in the $TiO_2$/ZnS composite, due to the decreased recombination between the excited electrons and holes.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2637-2642
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• 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.

• Journal of Environmental Science International
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• v.16 no.6
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• pp.683-688
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• 2007

In this study, N doped $TiO_2$ (TiO-N) thin film was prepared by DC magnetron sputtering method to show the photocatalytic activity in a visible range. Various gases (Ar, $O_2\;and\;N_2$) were used and Ti target was impressed by 1.2 kW -5.8 kW power range. The hysteresis of TiO-N thin film as a function of discharge voltage wasn't observed in 1.2 and 2.9kW of applied power. Cross sections and surfaces of thin films by FE-SEM were tiny and dense particle sizes of both films with normal cylindrical structures. XRD pattern of $TiO_2$ and TiO-N thin films was appeared by only anatase peak. Red shift in UV-Vis adsorption spectra was investigated TiO-N thin film. Photoactivity was evaluated by removal rate measurement of suncion yellow among reactive dyes. The photodegradation rate of $TiO_2$ thin film on visible radiation was shown little efficiency but TiO-N was about 18%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.4
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• pp.337-341
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• 2005

The degradation of IPA according to coating conditions was examined by $TiO_2/P-25-coated$ POF. In the photoactivity of $TiO_2-coated$ POF, ethanol solvent was higher activity than other solvents. Inorganic(KR-400), organic(A-9540) and inorganic$\cdot$organic hybrid(GPTMS, TMOS) resins were used as binder. Organic binder(A-9540) showed the highest activity for degradation of IPA, but organic binder was decomposed by $TiO_2$. Inorganic binder had lower binder ability than others, and lower adhesive than organic binders. In TMOS as inorganic · organic hybrid binder, activity of IPA degradation was decreased by addition of TMOS when the ratio of TMOS and P-25 was changed from 0.05 to 1.

• Analytical Science and Technology
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• v.21 no.3
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• pp.229-236
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• 2008

$C/TiO_2$ composites were prepared with surface modified MWCNT sequentially after HCl treatment and TNB as titanium source. There is a single crystal structure which is anatase in all of the samples from the data of XRD. The SEM microphotographs of $C/TiO_2$ composites show that the $TiO_2$ particles were well mixed with the CNT. There are C, O and Al with strong Ti peaks in all samples from EDX results, and it also shows that the sample CT has much more amount of C and Ti content than that of sample HCT. Finally, the photocatalytic activities for the $C/TiO_2$ composites have more effective than that of pristine $TiO_2$.

• Analytical Science and Technology
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• v.21 no.6
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• pp.553-561
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• 2008

$CNT/TiO_2$ composites were prepared by using multiwall carbon nanotubes (MWCNT) and various titanium alkoxide precursors. The composites were comprehensively characterized by scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), 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 the conversion of MB from model aqueous solution. Finally, according to the results of methylene blue (MB) removal experiment, we could see that sample CTOS have better MB removal effect than samples CTIP and CTPP.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.227.1-227.1
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• 2010

본 연구는 자외선 영역의 흡수로 전자 정공의 전하쌍을 생성함으로써 광전압 및 전류를 일으키는 티타니아 물질을 금속지지체 표면에 양극산화로 튜브형 $TiO_2$(anodized tubular $TiO_2$; ATT)로 제조한 후 나노크기의 금속 혹은 $WO_3$입자를 담지하여 광감응 재료로 활용하였다. 이는 기존의 입자나 콜로이드 형태로 광촉매 물질을 고정화하여 사용한 재료의 탈리현상 및 효율저하를 극복하기 위함이다. ATT는 전해질 내에 전기화학적 에칭율과 화학적 용해율의 비율에 의해 나노튜브 길이 성장에 영향을 미치는데 이를 유기 전해질과 불산 전해질을 사용하여 정전압 혹은 정전류의 조건에서 다양한 길이의 $TiO_2$ 나노튜브를 제조하였다. 여기에 전기분해담지(electrolytic deposition; ELD)를 통하여 정전류 조건에서 다양한 금속(Pt, Pd, Ru)을 나노크기의 형태로 담지하여 광촉매 내 생성된 전자 정공의 재결합을 줄이고자 하였고 $WO_3$의 담지를 통하여 가시광 감응을 높이고자 하였다. 제조된 여러 조건의 시료는 SEM과 EDAX를 통하여 형태와 길이, 담지량을 확인 하고 XRD를 이용하여 열처리 온도에 따른 결정화상태를 확인하였으며 광전류 측정 및 Cr(VI)의 광환원과 MB의 광분해를 통하여 광효율을 관찰하였다. 금속이 도핑되었을 경우 순수 ATT보다 보통 3배의 흡착률과 UV광원 아래 2배의 광효율을 관찰할 수 있었는데 이 중 Pt의 담지가 가장 효율이 좋았으며 흡착률에서는 담지량의 증가에 따른 증가선을 관찰 할 수 있었으나 광원 사용시 3%담지율에서 최적을 확인 할 수 있었다. 또한 $TiO_2$외 가시광감응 활성을 높이기 위한 다양한 광촉매제조가 진행 중에 있다.