• 한국세라믹학회지
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• 제22권3호
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• pp.19-24
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• 1985

The phtoelectrochemical porperties of $Nb_2O_5$, $Sb_2O_3$ and $V_2O_5$ doped and pure $SrTiO_3$ ceramic electodes were investigated. Shapes of I-V and I-λ characteristics of the pure $SrTiO_3$ ceramic electrode are similar to those of SrTiO3 single crystal electorde ; the anodic current strats at -0.9V (vs. Ag/AgCI) in 1 N-NaOH aqueous solution and the photoresponse appears at a wavelength of about 390nm and the quantum efficiency is about 3.5% at wavelength of 390nm under 0.5V vs. Ag/AgCl. Photocurrents of $Nb_2O_5$, $Sb_2O_3$ and $V_2O_5$ doped electrodes and $V_2O_5$ doped ceramic electrode appears at wavelength of 390nm and 500nm respectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2005년도 춘계학술발표대회 및 제8회 신소재 심포지엄 논문개요집
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• pp.82-82
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• 2005

• 대한금속재료학회지
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• 제46권11호
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• pp.730-736
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• 2008

$TiO_2$ nanotubes fabricated in aqueous HF-based electrolytes have been generally grown only to about 500nm in length because of the strong dissolubility of HF acid. In this paper, ethylene glycol solution has been applied for increasing the length of the anodic $TiO_2$ nanotubes, and the growth behaviors of the nanotubes according to water contents has been investigated. Anodization of Ti in ethylene glycol + 1 wt% $NH_4F$ (EG solution) with water additions up to 10 wt% were carried out at the constant voltage of 20 V. The results show that a thin titanium oxide layer is formed in the initial stage and the nanotube structure grows underneath the initial layer. And the length of $TiO_2$ nanotubes decreases with the increasing water content in the solution. It can be ascribed to the locally acidified circumstance around the barrier layer inside the nanopore due to $H^+$ ion originated from water. The XPS for the nanotubes suggests that the spectra of Ti2p and O1s are the major chemical bonding states of the $TiO_2$, and those for F1s, N1s and C1s come from the compound of $(NH_4)_2TiF_6$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.861-864
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• 2004

본 연구에서는 Ta이 도핑된 $TiO_2$와 $Au/TiO_2$ nanocomposite 박막을 co-sputtering법으로 제작하였다. Ta-doped $TiO_2$ 박막은 금흥석(rutile)에서 아나타제 상으로 변하는 구조를 유도하는 고용체를 형성했다. $Au/TiO_2$ nanocomposite film의 경우에는, 지름이 약 15 nm인 Au particles들이 $TiO_2$ matrix에 균질하게 분포되었다. Ta가 도핑된 $TiO_2$ 전극과 $Au/TiO_2$ 나노 콤포사이트 전극의 anodic photocurrents가 UV뿐만 아니라 가시광선 영역에서도 관찰되었다. Ta이 도핑된 $TiO_2$ 전극과 $Au/TiO_2$ 나노 콤포사이트 사이의 가시광선 영역에서 photoresponse는 계면 상태로 부터의 bandgap의 감소와 전자의 photoexcitation 때문이다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.48-48
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• 2001

• 한국재료학회:학술대회논문집
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• 한국재료학회 2006년도 추계학술발표대회 및 제11회 신소재 심포지엄
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• pp.34.1-34.1
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• 2006

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.421-429
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• 2020

This report describes the simultaneous detection of the two dyes most commonly used in food, tartrazine (TZ) and sunset yellow (SY), based on a microcomposite of carbon paste decorated with La₂O₃ and TiO₂. Anodic currents for SY-TZ were observed at 0.89-1.21 V by cyclic voltammetry (CV) separated with a ΔV of 0.32 V. The increased anodic peak currents compared to that of the unmodified carbon paste electrode were almost 50 and 41% for SY-TZ, respectively. The detection limits with the optimal amount of La₂O₃-TiO₂ were 0.02 and 0.03 µmol/L, respectively. The relative standard deviation (RSD) based on fifty measurements was less than 3%. The versatility and novelty of the sensor were tested with food samples containing these substances and other substances.

• 한국결정성장학회지
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• 제18권4호
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• pp.165-168
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• 2008

동시스퍼터법을 이용하여 Ta이 도핑된 $TiO_2$ 박막을 석영 및 ITO 기판위에 제작하였다. Ta의 도핑량은 동시스퍼터법에 의하여 조절되는 Ta 금속선 길이에 의하여 제어 되었다. Ta이 도핑된 $TiO_2$ 박막은 rutile상에서 anatase상으로 구조변화를 유발 시키며 고용체를 형성했다. Ta의 도핑량이 증가함에 따라 rutile상 보다는 anatase상이 많은 것으로 나타났다. XPS 분석에 따르면 도핑된 Ta은 금속이 아닌 $Ta_2O_5$의 산화물을 형성하는 것으로 나타났다. Ta이 도핑된 $TiO_2$ 전극에서는 자외선(UV) 영역을 포함하여 가시광(VIS) 영역의 빛의 조사에 광전류응답 특성을 발현하였다. 가시광선 영역에서 발현된 광전류 응답 특성은 Ta 도핑에 의하여 $TiO_2$ 밴드갭내에 불순물 준위의 형성에 기인한 것으로 사료된다.

• 한국표면공학회지
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• 제43권4호
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• pp.180-186
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• 2010

$TiO_2$ nanotubes were formed on Ti by anodizing in 1 M $H_3PO_4$ + 0.3 M HF and 0.1 M $NH_4F$ + 2% $H_2O$ in ethylene glycol, and their surface and cross-sectional morphologies were observed using FE-SEM as a function of anodizing time and applied voltage. The cross-section of the $TiO_2$ nanotubes was readily observed from the small pieces of nanotubes remaining near the scratch lines after scratching of the anodized surface. $TiO_2$ nanotubes was observed to grow faster and thicker in non-aqueous solution than in aqueous solution. Diameter of $TiO_2$ nanotubes was proportional to the applied voltage, irrespective of the type of the electrolyte, and it is recommended to use non-aqueous solutions for the preparation of larger diameter of $TiO_2$ nanotubes.

• 한국재료학회지
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• 제22권8호
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• pp.439-444
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• 2012

To compare the photocatalytic performances of titania for purification of waste water according to applied voltages and doping, $TiO_2$ films were prepared in a 1.0 M $H_2SO_4$ solution containing $NH_4F$ at different anodic voltages. Chemical bonding states of F-N-codoped $TiO_2$ were analyzed using surface X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the co-doped $TiO_2$ films was analyzed by the degradation of aniline blue solution. Nanotubes were formed with thicknesses of 200-300 nm for the films anodized at 30 V, but porous morphology was generated with pores of 1-2 ${\mu}m$ for the $TiO_2$ anodized at 180 V. The phenomenon of spark discharge was initiated at about 98 V due to the breakdown of the oxide films in both solutions. XPS analysis revealed the spectra of F1s at 684.3 eV and N1s at 399.8 eV for the $TiO_2$ anodized in the $H_2SO_4-NH_4F$ solution at 180 V, suggesting the incorporation of F and N species during anodization. Dye removal rates for the pure $TiO_2$ anodized at 30 V and 180 V were found to be 14.0% and 38.9%, respectively, in the photocatalytic degradation test of the aniline blue solution for 200 min irradiation; the rates for the F-N-codoped $TiO_2$ anodized at 30 V and 180 V were found to be 21.2% and 65.6%, respectively. From the results of diffuse reflectance absorption spectroscopy (DRS), it was found that the absorption edge of the F-N-codoped $TiO_2$ films shifted toward the visible light region up to 412 nm, indicating that the photocatalytic activity of $TiO_2$ is improved by appropriate doping of F and N by the addition of $NH_4F$.