Evaluation of Self-cleaning Property by Measuring Brightness of TiO2 Coating Ceramic Tileunder Outdoor Exposure Test

신대용,김경남 한국세라믹학회 2008 한국세라믹학회지 Vol.45 No.6

TiO2 coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using TiCl4 as a precursor. TiO2 film was formed on the ceramic tile by spray-coating technique and heat-treated at 500 o C for 1 h. The size and crystalline structure of TiO2 particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of TiO2 on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of TiO2 coating tile was affected by the coating amount of TiO2, however, not affected by the UV light intensity included in sun's ray (irradiation direction). TiO2 coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of TiO2 coating tile. TiO2 coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using TiCl4 as a precursor. TiO2 film was formed on the ceramic tile by spray-coating technique and heat-treated at 500 o C for 1 h. The size and crystalline structure of TiO2 particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of TiO2 on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of TiO2 coating tile was affected by the coating amount of TiO2, however, not affected by the UV light intensity included in sun's ray (irradiation direction). TiO2 coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of TiO2 coating tile.

TiO₂ 졸을 이용한 수중 Humic Acid의 광산화-화학적 산화법에 의한 부식산의 분해처리 기술에 관한 연구(I)-

석상일,안복엽,김미선,서태수,이동석,Seok, Sang Il,Ahn, Bok Yeop,Kim, Mi Sun,Suh, Tae Soo,Rhee, Dong Seok 대한환경공학회 2000 대한환경공학회지 Vol.22 No.6

가시광 영역에서 투명한 $TiO_2$ 졸을 이용하여 수중 humic acid의 광분해 특성을 고찰하였다. $TiO_2$ 졸은 $TiCl_4$ 용액의 가수분해 침전물인 $TiO(OH)_2$를 $H_2O_2$와 반응시켜 titanium peroxo solution (TPS)을 제조한 후, 이 용액을 온도와 시간의 함수로 열처리하여 제조하였다. Humic acid의 광분해를 위하여 사용된 졸의 적정 농도는 100ppm 전 후이었으며, photoluminescence(PL)를 이용하여 결정되었다. $TiO_2$ 졸의 humic acid에 대한 광촉매 효능은 TPS를 $100^{\circ}C$에서 12시간 이상 열처리한 졸을 이용할 때 가장 높았으며, 상용되고 있는 Degussa P25 보다 우수한 것으로 나타났다. 또한 상용의 분말로부터 유도된 현탁 반응은 처리수가 $TiO_2$로 인해 높은 탁도를 나타내는 반면, TPS로부터 유래한 졸은 거의 탁도를 나타내지 않고 높은 투명성을 보였다. The photo-oxidation of an aqueous humic acid solution using $TiO_2$ sols. which is transparent in visible range, was studied. The $TiO_2$ sols were prepared by a process wherein hydrogen peroxide was added to a gel of $TiO(OH)_2$ originated from hydrolysis of $TiCl_4$, and the resulting titanium peroxo solution(TPS) was heated. The concentration of $TiO_2$ used for photo-oxidation was about 100ppm, determined by comparing the photoluminescence(PL) intensity measured as a function of $TiO_2$ concentration. $TiO_2$ sols aged at $100^{\circ}C$ for more than 12h were found to exhibit a maximum rate in photocatalytic decomposition of humic acid. and the efficiency was better than that of Degussa P25. In addition, the resulting aqueous humic acid after photocatalytic decomposition with sols had an excellent transmittance of visible light, while that treated with Degussa P25 was still turbid. caused by $TiO_2$ particles.

자기세정을 위한 스퍼터링 TiO2 박막의 산소 표면처리에 따른 특성

박용섭,김남훈 한국전기전자재료학회 2016 전기전자재료학회논문지 Vol.29 No.5

Titanium oxide (TiO2) thin films were fabricated by unbalanced magnetron (UBM) sputtering. The fabricated TiO2 films were treated by oxygen plasma under various RF powers. We investigated the characteristics of oxygen plasma treatment on the surface, structural, and physical properties of TiO2 films prepared at various plasma treatment RF powers. UBM sputtered TiO2 films exhibited higher contact angle value, smooth surface, and amorphous structure. However, the rms surface roughness TiO2 films were rough, and the contact angle value was decreased with the increase of the plasma treatment RF power Also, the hardness value of TiO2 film as physical properties was slightly increased with the increase of the plasma treatment RF power. In the results, the performance of TiO2 films for self cleaning critically depended on the with the plasma treatment RF power. TiO2 박막은 비대칭 마그네트론 스퍼터링 장치에 의해 제작되었다. 제작되어진 TiO2 박막은 다양한 산소플라즈마 rf 파워에 따라 표면 처리되었다. 스퍼터링되어진 TiO2 박막은 다양한 산소플라즈마 조건에 의해 표면 처리되었으며, 표면 처리되어진 박막들의 표면 특성, 구조, 물리적 특성 등을 고찰하였다. 비대칭 마그네트론 스퍼터링되어진 TiO2 박막은 높은 접촉각 값을 나타내었고, 부드러운 표면, 그리고 비정질 구조 특성을 나타내었다. 그러나 스퍼터링되어진 TiO2 박막은 산소플라즈마 rf 파워가 증가함에 따라 rms 표면 거칠기 값은 감소하였고, 물리적 특성인 박막의 경도 값은 산소플라즈마 rf 파워의 증가에 따라 약간 증가하였다. 결과적으로 TiO2 박막의 자기세정 특성은 표면처리를 위한 산소 플라즈마 rf 파워에 의존한다.

TiO₂ Interlayer의 상변화에 따른 PLZT 박막의 구조 및 전기적 특성

이철수,윤지언,황동현,차원효,손영국,Lee, Chul-Su,Yoon, Ji-Eon,Hwang, Dong-Hyun,Cha, Won-Hyo,Sona, Young-Gook 한국진공학회 2007 Applied Science and Convergence Technology Vol.16 No.6

R.F. magnetron-sputtering 방법에 의해 $(Pb_{1.1},La_{0.08})(Zr_{0.65}.Ti_{0.35})O_3$ 박막을 $Pt/Ti/SiO_2/Si$, $TiO_2(interlayer)/Pt/Ti/SiO_2/Si$ 기판에 증착하고, $TiO_2$ interlayer에 의한 PLZT 박막의 특성을 고찰 하였다. $TiO_2$ interlayer의 증착조건을 변화시켜가며 단일상의 anatase 상과 rutile 상을 증착하였고, 그 위에 증착시킨 PLZT 박막의결정성을 x-ray diffraction(XRD)을 통해 분석하였다. 또한 $TiO_2$ interlayer에 의한 $PLZT-TiO_2$, $TiO_2-Pt$ 박막의 계면상태를 고찰하기 위해 glow discharge spectrometer(GDS) 분석을 행하였고, PLZT의 강유전 특성을 고찰하기 위해 전기적 측정을 행하였다. $TiO_2$ anatase 단일 상에 증착한 PLZT의 경우 (110) 방향으로 우선 배향됨을 알 수 있었고, 12.6 ${\mu}C/cm^2$의 잔류분극 값을 나타내었다. [ $(Pb_{1.1},La_{0.08})(Zr_{0.65}.Ti_{0.35})O_3$ ] thin films on the $Pt/Ti/SiO_2/Si$, $TiO_2(interlayer)/Pt/Ti/SiO_2/Si$ substrate were fabricated by the R.F. magnetron-sputtering method and considered their characteristics depending on $TiO_2$ interlayer. Changing the deposition conditions of $TiO_2$ interlayer, we obtained $TiO_2$ anatase single phase and rutile single phase. PLZT was deposited on these substrates and analyzed by x-ray diffraction(XRD) for there crystallinity and orientation. To investigate $PLZT-TiO_2$, $TiO_2-Pt$ interface, glow discharge spectrometer(GDS) analysis was carried out and we performed electrical measurements for dielectric properties of PLZT thin films. The PLZT thin film on $TiO_2$ anatase interlayer was found to have (110)-preferred orientation and 12.6 ${\mu}C/cm^2$ remaining polarization value.

원자층 증착장치에 의한 TiO2 박막 코팅된 폴리머 절연체의 표면 및 전기적 특성의 향상

박용섭,김남훈 한국전기전자재료학회 2016 전기전자재료학회논문지 Vol.29 No.7

Titanium oxide (TiO2) thin films were synthesized on polymer insulator and Si substrates by atomic layer deposition (ALD) method. The surface and electrical properties of TiO2 films synthesized at various ALD cycle numbers were investigated. The synthesized TiO2 films exhibited higher contact angle and smooth surface. The contact angle of TiO2 films was increased with the increase of ALD-cycle number. Also, the rms surface roughness of films was slightly rough with the increase of ALD-cycle number. The leakage current on TiO2 film surface synthesized at various conditions were uniformed, and the values were decreased with the increase of ALD-cycle number. In the results, the performance of TiO2 films for self-cleaning critically depended on a number of ALD-cycle. TiO2 박막은 원자층 증착 장치(ALD)를 이용하여 폴리머 절연체와 실리콘 기판위에 합성하였다. 다양한 ALD 사이클 수에 따라 제작되어진 TiO2 박막의 표면과 전기적 특성이 고찰되었다. 합성되어진 TiO2 박막은 높은 접촉각과 부드러운 표면을 나타내었다. 도한 TiO2 박막의 접촉각은 ALD 사이클 수가 증가함에 따라 증가하였다. 박막의 rms 표면 거칠기 값은 ALD 사이클 수의 증가에 따라 약간 거칠어 졌다. 다양한 조건에서 합성되어진 TiO2 박막 표면에서 누설전류 값은 균일하였고, 이 값은 ALD 사이클 수의 증가에 따라 감소하였다. 결과로서 자기세정 응용을 위한 TiO2 박막의 특성들은 ALD 사이클 수에 의존하는 것을 확인하였다.

TiO₂ (bottom)/Fe-TiO₂ (top) 이중 층 필름 위에서 CO₂ 광 환원에 의한 효과적인 메탄 제조

도정연,강미숙,임영환,곽병섭,김주용 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

In this study, TiO₂ and x mol. % Fe-doped TiO₂ were prepared using a conventional solvothermal method, and the prepared powders were fabricated as TiO₂/Fe-TiO₂ double-layered films for applications to the photoreduction of CO₂. The amount of CH₄ generated from the photoreduction of CO₂ with H₂O increased remarkably over the TiO₂/Fe-TiO₂ films compared to the TiO₂/TiO₂ film. In particular, the amount of CH₄ gas evolved over the TiO₂/1.0 mol. % Fe-TiO₂ film was 7 times higher than that produced over the TiO₂/TiO₂ film. A proposed model suggested that the photoactivity over the TiO₂/Fe-TiO₂ films can be enhanced by the effective charge separation and inhibited recombination of photogenerated electron-hole (e-/h+) pairs on interfacial transfer between TiO₂ and Fe-TiO₂.

TiO₂ 함유 피치섬유의 최적 안정화 조건

엄상용,이창호,박관호,유승곤,Eom, Sang Yong,Lee, Chang Ho,Park, Kwan Ho,Ryu, Seung Kon 한국화학공학회 2007 Korean Chemical Engineering Research(HWAHAK KONGHA Vol. No.

$TiO_2$ 함유 피치섬유의 최적 안정화 조건을 도출하기 위하여 $TiO_2$의 함유량을 달리하여 피치섬유를 제조한 후, 여러가지 안정화 조건에 대한 섬유의 특성 변화와 금속입자의 거동을 관찰하였다. 공기에 의한 피치섬유의 안정화시 안정화온도가 높고, $TiO_2$ 함유량이 적을수록 산화에 의한 무게증가가 컸다. 안정화된 섬유를 탄화하면 수율은 71~82 wt.% 수준인데, $TiO_2$가 활성촉매 역할을 하여 $TiO_2$의 함유량이 많을수록 탄화수율은 낮았다. 안정화 과정에서 열가소성의 피치섬유는 산소의 도입으로 카르보닐기(C=O)와 카르복실기(-COOH) 등이 형성되며 동시에 이들이 가교결합을 이루고 수소를 탈리시켜 열경화성 섬유로 전환되었다. 활성탄소섬유의 기공크기는 $TiO_2$ 함유량이 증가함에 따라 점점 커졌으며, 주사전자현미경과 투과전자현미경을 통하여 섬유의 표면과 내부에 분포된 $TiO_2$ 입자와 분포를 관찰한 결과 안정화, 탄화 및 활성화공정 중 일부 $TiO_2$가 서로 뭉침을 알 수 있었다. 최종적으로 0.5 wt.% $TiO_2$ 함유 석유계 피치섬유는 $280^{\circ}C$에서 3 hr를 최적 안정화 조건으로 제시할 수 있었다. $TiO_2$-containing pitch fibers were prepared and various stabilization variables were investigated by characterizations of the fibers and behaviors of $TiO_2$ particles in the optimum stabilization conditions. When pitch fiber was stabilized by air at the optimum condition, the fiber weight increased as an increase of the stabilization temperature and a decrease of $TiO_2$ concentration. The carbonization yield was 71~82 wt.%, showing a decrease of the yield with the $TiO_2$ increase caused by the catalytic activity of $TiO_2$ to combustion. During the stabilization, newly developed carbonyl and carboxyl groups were introduced on the fiber surface and cross-linking reactions were progressed resulting the thermosetting property, which was verified by the replacement of hydrogen with oxygen. Pore size of the activated carbon fiber was increased by an increase in $TiO_2$ concentration. In the considerations of the aggregation behaviors of the $TiO_2$ particles, the optimum stabilization conditions of 0.5 wt.% $TiO_2$ containing petroleum-based pitch fiber were suggested as $280^{\circ}C$, 3 hr.

주형합성을 통한 메조포러스 TiO₂ 제조 및 실리카 메조포어 내부에서의 TiO₂ 상전이 거동 변화

방경민 ( Gyeong-min Bang ),김영지 ( Young-ji Kim ),김승한 ( Seung Han Kim ),최예락 ( Yerak Choi ),이인호 ( In Ho Lee ),고창현 ( Chang Hyun Ko ) 한국화학공학회 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.2

본 연구에서는 수열합성법과 주형합성법을 이용하여 메조포어를 지닌 TiO₂를 합성하였다. 수열합성법을 이용해서 anatase 구조의 메조포러스 TiO₂를 합성했다. Rutile 구조의 메조포러스 TiO₂를 제조하기 위해서 수열합성법으로 제조된 메조포러스 TiO₂를 300 ℃부터 700 ℃까지 소성시켰더니 600 ℃부터 anatase에서 rutile 결정구조로 상전이가 일어났다. 하지만, 메조포어가 붕괴되었다. 메조포어을 지닌 TiO₂를 합성하기 위해서 메조포러스 실리카 KIT-6을 주형으로 사용하는 주형합성법을 사용하였다. 먼저 메조포어 내부에 TiO₂를 형성시키고 소성 온도를 800, 900 ℃로 높여서 anatase에서 rutile로의 상전이 거동을 조사하였다. 수열합성을 통해 제조된 자유로운 상태의 메조포러스 TiO₂의 경우 600 ℃에서 anatase에서 rutile로의 상전이가 일어났지만 제한된 공간인 메조포러스 기공 내부에 형성된 TiO₂의 경우 800 ℃까지 가열하더라도 rutile구조로 상전이가 일어나지 않았고, 900 ℃로 소성시키자 일부의 anatase가 rutile로의 상전이가 일어나기 시작하였다. 이러한 상전이는 산소 빈자리의 형성에 의해서 일어나야 한다고 알려져 있지만 실리카 기공 내부에 형성된 TiO₂는 실리카 기공 표면이 산소 빈자리 형성을 방해해서 상전이가 억제되는 것으로 판단된다. 900 ℃의 높은 소성온도로 인해서 anatase와 rutile 구조가 섞여있으며 실리카 기공 내부에 형성된 TiO₂는 NaOH 수용액을 이용해서 주형인 KIT-6과 분리해서 메조포어를 지닌 TiO₂를 제조하였다. To prepare mesoporous TiO₂ (meso-TiO₂) with anatase and rutile crystal structures, hydrothermal and template synthesis were used. Meso-TiO₂ with anatase structure was obtained by hydrothermal synthesis. The crystal structure of meso-TiO₂ by hydrothermal synthesis converted from anatase to rutile by simple heating at 600 ℃ and above. However, their mesopore structure collapsed due to phase transition. To prepare meso-TiO₂ with rutile structure, template synthesis method was applied using mesoporous silica KIT-6 as a template. Once we incorporated anatase TiO₂ inside mesopores of silica, the phase transition temperature of TiO₂ confined inside KIT-6 was much higher (900 ℃) than that of free-standing TiO₂ (600 ℃). The suppression of TiO₂ phase transition inside mesopores of KIT-6 is closely related with the interaction between TiO₂ surface and silica walls in KIT-6 because oxygen vacancy in TiO₂ is regarded as the starting point for phase transition. After removal of silica template by NaOH solution washing, meso-TiO₂ with mixed phase between anatase and rutile was obtained.

SiO₂-TiO₂계 복합 나노섬유의 제조 및 광활성 연구

현동호,임태호,이성욱,Hyun, Dong Ho,Lim, Tae-Ho,Lee, Sung Wook 한국공업화학회 2008 공업화학 Vol.19 No.5

전구체로서 알콕사이드[Tetraethyl orthosilicate (TEOS), Titanium (IV) isopropoxide (TiP)]를 사용하여 졸-겔 방법으로 전기방사에 적합한 졸을 제조한 후, $(1-x)SiO_2-(x)TiO_2$계 복합 나노섬유를 제조하였다. 제조된 광활성 무기나노섬유의 표면 및 구조적 특성은 X-선회절분석(XRD), 주사전자현미경(SEM), 투과전자현미경(TEM), 열중량분석 및 미분주사칼로리미터분석 (TGA-DSC), 적외선분광분석((FT-IR)을 통하여 확인하였다. $(1-x)SiO_2-(x)TiO_2$계에서 $TiO_2$ 양이 증가하면 전기방사된 복합섬유직경은 증가하였으며, 저온에서 안정한 아나타제 $TiO_2$ 결정에서 루타일로의 상전이는 $1000^{\circ}C$에서의 열처리 후에도 고루 분산되어 있는 $SiO_2$로 인해 $0.6SiO_2-0.4TiO_2$계까지는 아나타제상으로 존재하였다. $SiO_2-TiO_2$계 복합체 나노섬유의 광활성은 메틸렌블루 광분해 실험 및 UV-vis/DRS 분석을 통해 자외선 영역에서 나타남을 확인하였다. $(1-x)SiO_2-(x)TiO_2$ composite fibers with various compositions of $TiO_2$ were prepared by electrospinning their sol-gel precursors of titanium (IV) iso-propoxide (TiP), and tetraethyl orthosilicate (TEOS). The surface morphology and structure of sintered composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), simultaneous thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and Fourier transform infrared spectroscopy (FT-IR). As the content of $TiO_2$ in $(1-x)SiO_2-(x)TiO_2$ system was increased the average diameter of composite fibers was proportionally increased. Also, the transformation of $TiO_2$ from anatase to rutile form was inhibited by the highly dispersed $TiO_2$ around $SiO_2$ particles up to $0.6SiO_2-0.4TiO_2$ composite fibers even after calcination at $1000^{\circ}C$. The photocatalytic activity of $SiO_2-TiO_2$ composite fibers was examined for the methylene blue (MB) decomposition which was confirmed using UV-vis/DRS spectra. The experiments demonstrated that the MB in aqueous solution was successfully photodegraded using $SiO_2-TiO_2$ composite nanofibers under UV-visible light irradiation.

Synthesis of new TiO₂/porphyrin-based composites and photocatalytic studies on methylene blue degradation

Min, Kyeong Su,Kumar, Rangaraju Satish,Lee, Jeong Hoon,Kim, Kang Seok,Lee, Seung Geol,Son, Young-A. Elsevier 2019 Dyes and pigments Vol.160 No.-

<P><B>Abstract</B></P> <P>In this study, we synthesized porphyrin dyes and structurally characterized them using <SUP>1</SUP>H and <SUP>13</SUP>C NMR and FT-IR and high-resolution mass spectrometry. By using these porphyrins, new TiO<SUB>2</SUB>-porphyrin catalysts (<B>TiO</B> <SUB> <B>2</B> </SUB> <B>-PORPC-1</B>, <B>TiO</B> <SUB> <B>2</B> </SUB> <B>-PORPC-2, TiO</B> <SUB> <B>2</B> </SUB> <B>-PORPC-3</B> and <B>TiO</B> <SUB> <B>2</B> </SUB> <B>-PORPC-4</B>), were prepared and the structures of these catalysts were confirmed by using SEM, TEM, solid-state UV-visible spectroscopy, XPS, FT-IR spectroscopy and EDS analysis. Studies on the photodegradation of methylene blue suggested that our TiO<SUB>2</SUB>-porphyrin photocatalysts were more effective for the degradation than bare TiO<SUB>2</SUB>-anatase, and furthermore, TiO<SUB>2</SUB>-Zn-porphyrins showed better photocatalytic activity than the metal-free TiO<SUB>2</SUB>-porphyrins because of their high charge-transfer properties. We evaluated the stability of the TiO<SUB>2</SUB>-porphyrins by repeatability test. Finally, we proposed a plausible mechanism for the photocatalytic activity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel TiO<SUB>2</SUB>-porphyrin catalysts were prepared and characterized. </LI> <LI> Photocatalysts showed high activity in Methylene Blue (MB) degradation. </LI> <LI> TiO<SUB>2</SUB>-porphyrin photocatalysts were more effective than bare TiO<SUB>2</SUB>-anatase. </LI> <LI> TiO<SUB>2</SUB>-Zn-porphyrins showed better activity than nonmetalated TiO<SUB>2</SUB>-porphyrins. </LI> <LI> The plausible photocatalytic mechanism was projected. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>