• 한국세라믹학회지
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• 제46권4호
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• pp.357-364
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• 2009

We investigate a method for the electrochemical preparation of titanium dioxide/carbon nanotube ($TiO_2$/CNT) composites involving the electroplating of Ti in a titanium n-butoxide (TNB) electrolyte into a CNT matrix. The BET surface areas of $TiO_2$/CNT composites decreased as electrochemical operating time increased. Changes in XRD patterns showed a typical anatase type on the $TiO_2$/CNT composite prepared with a CNT matrix by the electroplating method in the TNB solution. In SEM micrographs, the titanium complex particles were uniformly distributed on the CNT surface. The results of chemical elemental analysis for the $TiO_2$/CNT composites showed that most of the spectra for these samples produced stronger peaks for carbon and Ti metal than those of any other element. Finally, the prominent photoelectrocatalytic (PEC) activities of the $TiO_2$/CNT composites could be attributed to the combined effects of photodegradation of $TiO_2$, electron assistance of CNT and the application of a sufficient voltage.

• 분석과학
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• 제14권3호
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• pp.259-265
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• 2001

ZnO, CdS, rutile-$TiO_2$ 및 혼합 rutile-$TiO_2$/ZnO와 같은 여러 반도체를 이용하여 Congo Red를 광 촉매 분해시켰다. 연구 결과 ZnO, CdS, rutile-$TiO_2$ 중에서는 CdS의 광 촉매 효과가 제일 컸는데 이것은 CdS가 제일 작은 band gap 에너지를 가지고 있기 때문이었다. 또한 혼합 촉매에서는 ZnO의 함량이 rutile-$TiO_2$에 비하여 상대적으로 높을수록 분해 반응을 촉진하였다. 이것은 $Zn^{2+}$ 가수분해 생성물이 구조적으로 안정한 화합물인 rutile-$TiO_2$의 표면을 덮음으로서 자외선 흡수를 차단하기 때문에 라디칼 생성을 저해하기 때문이었다.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.776-782
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• 2015

$TiO_2$ 나노입자의 광촉매 반응을 억제하기 위해 평균 직경 3~5 nm의 $TiO_2-SnO_2$ 나노입자가 titanium tetraisopropoxide(TTIP)와 tin chloride의 가수분해 반응에 의해 합성되었다. 생성된 $TiO_2-SnO_2$ 나노입자를 졸-겔법에 의해 3-glycidoxypropyl trimethoxysilane(GPTMS)과 반응시킴에 의해 유-무기 혼성 코팅 용액이 제조되었다. 그 후 코팅 용액을 기재인 polycarbonate(PC) 시트 위에 스핀 코팅시키고, $120^{\circ}C$에서 열경화 시켜 고굴절률 하드코팅 도막이 제조되었다. $TiO_2-SnO_2$ 나노입자로부터의 코팅 도막은 $TiO_2$ 나노입자로부터 얻어진 코팅 도막의 2H에 비해 증가된 3H의 연필경도를 보였다. 또한 $TiO_2-SnO_2$ 나노입자로부터의 코팅 도막의 굴절률은 Sn/Ti 몰 비가 0에서 0.5로 증가함에 따라 633 nm 파장에서 1.543으로부터 1.623으로 향상되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.94-96
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• 2002

The $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%) were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature by XRD and SEM. According to the X-ray diffraction patterns of the $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%), the ilmenite $MgTiO_3$ and perovskite $SrTiO_3$ structures were coexisted and secondary phase $MgTi_2O_5$ were appeared. Increasing the sintering temperature. the grain size was increased. In the case of $0.97MgTiO_3-0.03SrTiO_3$ ceramics with $B_2O_3$(10wt%), dielectric constant, quality factor and temperature coefficient of resonant frequency were $13.52{\sim}18.13,\;32750{\sim}51736GHz$, $-15.78{\sim}25.64ppm/^{\circ}C$, respectively.

• 한국재료학회지
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• 제7권2호
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• pp.114-120
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• 1997

$Ba(NO_{3})_{2}$와 $TiCl_{4}$의 혼합 수용액으로부터 전기화학법 중 음극혼원법(cathodic reduction method)을 이용하여 stainless steel기판 위에 $BaTiO_{3}$박막을 제조하였다. $BaTiO_{3}$전구체 박막은 혼합 수용액으로부터 반응초기에 $TiO_{2}{\cdot}nH_{2}O$M/형태로 우선적으로 형성되었으며, 일정 시간이 경과한 후에는 일정한 Ba/Ti몰비를 갖는 박막이 제조되었다. $BaTiO_{3}$박막 내 Ba/Ti조성비는 혼합 수용액 내에 존재하는 이온 조성비 $Ba^{2+}/Ti_{4+}$에 변화하였는데, 0.3M $Ba(NO_{3})_{2}$와 0.1M $TiCI_{4}$의 혼합 수용액과 $10mA/cm^2$의 전류를 흘려주는 조건에서 Ba/Ti의 조성비가 1에 가까운 박막을 얻을 수 있었다. 이러한 전구체 박막을 $500^{\circ}C$이상에서 열처리한 결고 페로브스카이트 상의 $BaTiO_{3}$박막이 제조되었다.

• 한국세라믹학회지
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• 제41권7호
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• pp.548-554
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• 2004

슬러리 발포법을 이용하여 다공성 실리카 지지체를 제조하였으며, 지지체 표면에 졸-겔법을 이용하여 TiO$_2$을 코팅하였다. TiO$_2$ 코팅층에 대한 XRD, SEM 및 BET 측정 결과, 열처리 온도가 50$0^{\circ}C$에서 TiO$_2$의 anatase 결정상이 나타나기 시작하여, $700^{\circ}C$에서 그 피크가 최대가 되었다. 이 때 결정 성장한 TiO$_2$ 입자의 크기는 약 1$mu extrm{m}$ 정도로 판명되었다. 또한, 촉매지지체로 활용성을 검토하기 위해 TiO$_2$코팅 전후로 지지체의 굽힘 강도와 기체 투과율을 측정하였다. 강도의 경우, 코팅 전 2.4 MPa에서 이후 3.9∼4.3MPa로 증가하였으나 열처리 온도의 영향에 의한 변화는 나타나지 않았다. 한편, 투과율은 코팅 전 770${\times}$$10^{-13}$ $m^2$에서 코팅 후 363${\times}$$10^{-13}$ $m^2$로 감소하였고 열처리 온도의 증가와 함께 감소하는 것으로 나타났다.

• 한국결정성장학회지
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• 제17권1호
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• pp.23-29
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• 2007

Pitch-coated anatase $TiO_2$ typed was prepared by $CCl_4$ solvent mixing method with different mixing ratios. Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the pitch-coated $TiO_2$ sample series showed a good adsorptivity and photo decomposition activity. The BET surface area for the carbon layer in the sample increases to increasing with pitch contents. The SEM results present to the characterization of porous texture on the pitch-coated $TiO_2$ sample and pitch distributions on the surfaces for all the materials used. From XRD data a weak and broad carbon peak of graphene with pristine anatase peaks were observed in the X-ray diffraction patterns for the pitch-coated $TiO_2$. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of pitch-coated $TiO_2$ with slope relationship between relative concentration of MB ($c/c_o$) and t could be attributed to the homogeneous coated pitch on the external surface by $CCl_4$ solvent method.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2295-2298
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• 2014

To effectively destruct 2-chlorophenol, a representative sterile preservative, nanometer-sized Mn (0.5, 1.0, 3.0 mol %)-incorporated $TiO_2$ powders were synthesized by a solvothermal method. XRD result demonstrated that the Mn ingredients were perfectly inserted into $TiO_2$ framework. The Mn-$TiO_2$ particles exhibited an anatase structure with a particle size of below 20 nm. The absorbance was shifted to the higher wavelength on Mn-$TiO_2$ compared to that of $TiO_2$. Otherwise, the PL intensities which has a close relationship for recombination between holes and electrons significantly decreased on Mn-$TiO_2$. The photodecomposition for 2-chlorophenol in a liquid system was enhanced over Mn-doped $TiO_2$ compared with pure $TiO_2$: 2-chlorophenol of 50 ppm was completely decomposed after 12 h when 1.0 mol % Mn-$TiO_2$ was used. Consequently, the core of this paper is as follows. introducing Mn into $TiO_2$ framework reduced the band-gap, moreover, it played as an electron capture resulted to lower recombination between electrons and holes during photocatalytic reaction for removal of 2-cholophenol.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2660-2664
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• 2014

A simple method of depositing titanium dioxide ($TiO_2$) nanoparticles onto graphene oxide (GO) as a catalytic support was devised for photocatalytic degradation of methylene blue (MB). Thiol groups were utilized as linkers to secure the $TiO_2$ nanoparticles. The resultant GO-supported $TiO_2$ (GO-$TiO_2$) sample was characterized by transmission electron microscopy (TEM), near-edge X-ray absorption fine structure (NEXAFS), and X-ray photoelectron spectroscopy (XPS) measurements, revealing that the anatase $TiO_2$ nanoparticles had effectively anchored to the GO surface. In the photodegradation of MB, GO-$TiO_2$ exhibited remarkably enhanced photocatalytic efficiency compared with thiolated GO and pure $TiO_2$ nanoparticles. Moreover, after five-cycle photodegradation experiment, no obvious deactivation was observed. The overall results showed that thiolated GO provides a good support substrate and, thereby, enhances the photodegradation effectiveness of the composite photocatalyst.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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• pp.109-110
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• 2006

Nanocrystalline $TiO_2$ electrode were prepared by spray-printing in order to efficiency and improved fill factor. Different compositions of nanocrystalline $TiO_2$ pastes are described, based on $TiO_2$ powder made by ourselves. The produced by spray printing $TiO_2$ films were compare with the produced by squeeze printing $TiO_2$ films and was studied in the light of static I-V characteristics. The produced $TiO_2$ films are extensively characterized by means of spectroscopy(Ramon, XRD) and microscopy(FE-SEM).