메조기공의 실리카-티타니아 코겔의 제조와 자율적 조습 및 광촉매 특성

이상화; 곽중협; 서태수; 김효중; 김동표; Sang Hwa Lee; Chung-Heop Kwak; Tae-Soo Suh; Hyo-Joong Kim; Dong=Pyo Kim

Journal of the Korean Industrial and Engineering Chemistry, Vol.14, No.3, 298-306, May, 2003

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메조기공의 실리카-티타니아 코겔의 제조와 자율적 조습 및 광촉매 특성

Preparation of the Mesoporous Silica-Titania Cogel and Its Humidity Self-control and Photocatalytic Properties

이상화, 곽중협 ^†, 서태수 , 김효중 , 김동표 ¹

한국화학연구원, 대전 305-600
¹충남대학교 공업화학과, 대전 305-764

Sang Hwa Lee, Chung-Heop Kwak^†, Tae-Soo Suh , Hyo-Joong Kim , and Dong=Pyo Kim¹

Advanced Material Division 2, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea
¹Department of Industrial Chemistry Engineering, Chungnam National University, Daejeon 305-764, Korea

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초록

수용액상의 졸겔반응에 의해 메조기공의 실리카-티타니아 코겔을 제조하고 이들의 자율적 조습력과 광촉매 특성에 대해 검토하였다. 실리카-티타니아 코겔에 있어 조습력과 관계되는 세공크기와 용적은 본 연구에서 고안된 역적정법에 의해 pH 7부근 및 SiO₂/TiO₂ 비가 상대적으로 큰 9/1인 경우에 가장 큰 생성물이 얻어졌다. 페놀 분해율에 의한 광촉매 특성은 동일조건에서 SiO₂/TiO₂ 비가 감소함에 따라 증가하였고, SiO₂/TiO₂ 비가 9/1에서 세공크기 4.0 ~ 6.0 nm 및 세공용적 0.6 ~ 0.8 mL/g 범위로 제어된 코겔의 경우 환경습도 40 ~ 70 % 범위에서의 흡습량 25%, 방습량 45%로서 종래 조습제료 보다 자율조습력이 큰 것을 볼 수 있었고, 같은 조성의 실리카-티타니아 혼합 산화물과의 페놀 분해율에 의한 광촉매 특성 비교에서도 우수한 물성을 보이고 있었는데 이것은 Ti-O-Si 결합형성으로 인해 코겔 구조내에 음전하 과잉으로 인한 활성점(브렌스테드 산점) 발현에 기인된 것으로 고찰된다.

Silica-titania cogel materials have been prepared by aqueous sol-gel process using a back titration technique designed for this study. The humidity self-control and photocatalytic properties of the materials have been also investigated. In these silica-titania cogel materials, relatively large pore size and pore volume that can give a good humidity control ability are desired, and they were synthesized under theh reaction condition at pH of 7 and SiO₂/TiO₂ ratio of 9/1. The photocatalytic property, which was measured by the decomposition ratio of phenol, increased with the decrease of SiO₂/TiO₂ ratio in the composition. The cogel at the SiO₂/TiO₂ ratio of 9/1, resulted in the pore size of 4.0 ~ 6.0 nm and the pore volume of 0.6 ~ 0.8 mL/g. At the relative humidity range of 40 ~ 70%, the amounts of moisture absorption and desorption were 25% and 45%, respectively, and these had a better humidity control ability than conventional ones. In addision, the cogel showed a superior photocatalytic property compared to that of silica and titania mixture with the same composition. This encancement is probably due to the revelation of active sites by the excess negative charges that were induced by Ti-O-Si bond formation in the cogel structure.

Keywords:humidity self-control materials;mesoporous silica-titania cogel;water vapor isotherm plot;photocatalytic reaction

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Sterte J, Shabtai J, Clays Clay Miner., 35, 429 (1987)
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Kresge TC, Nature, 359, 710 (1992)
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Brinker CJ, Scherer GW, Sol-Gel Science 3, 99, Academic Press, New York (1990)
Iler RK, The Chemistry of Silica, 3, 105, Wiley, New York (1979)
Bergna HE, The Colloid Chemistry of Silica, 2, 51, American Chem. Soc., Washington D.C. (1994)
Gao XT, Wachs IE, Catal. Today, 51(2), 233 (1999)
Miller JB, Johnston ST, Ko EI, J. Catal., 150(2), 311 (1994)
Gunji T, Kasahara T, Abe Y, J. Sol-Gel Sci. Tech., 13, 975 (1998)
Liu ZF, Crumbaugh GM, Davis RJ, J. Catal., 159(1), 83 (1996)
Ding Z, Zhu HY, Greenfield PF, Lu GQ, J. Colloid Interface Sci., 238(2), 267 (2001)
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Tanabe K, Bull. Chem. Soc. Jpn., 47, 1064 (1974)
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Brinker CJ, Schere GW, Roth EP, J. Non-Cryst. Solids, 72, 345 (1985)
Kwak CH, Yang JS, Suh TS, Kim HJ, Choi CS, J. Korean Ind. Eng. Chem., 11(4), 402 (2000)
Yang JS, Kwak CH, Suh TS, Choi CS, J. Korean Ind. Eng. Chem., 11(8), 944 (2000)

[Related Articles]

[1] Fujida M, JETI, 41(3), 111 (1993)

[2] Lynch TJ, Pa O, U.S. Patent, 3,977,993 (1976)

[3] Okada K, Kawabima H, Saito Y, Hayashi S, Yasumori A, J. Mater. Chem., 5(8), 1241 (1995)

[4] Sterte J, Shabtai J, Clays Clay Miner., 35, 429 (1987)

[5] Inagaki S, Fukusima Y, J. Soc. Powder Technol. Jpn., 33, 868 (1996)

[6] Beck JS, J. Am. Chem. Soc., 114, 10834 (1992)

[7] Kresge TC, Nature, 359, 710 (1992)

[8] Kimura K, Tanaka H, Gypsum Lime(246), 1069 (1993)

[9] Ding Z, Zhu HY, Lu GQ, Greenfield PF, J. Colloid Interface Sci., 209(1), 193 (1999)

[10] Park DG, Polym. Sci. Technol., 8(3), 248 (1997)

[11] Brinker CJ, Scherer GW, Sol-Gel Science 3, 99, Academic Press, New York (1990)

[12] Iler RK, The Chemistry of Silica, 3, 105, Wiley, New York (1979)

[13] Bergna HE, The Colloid Chemistry of Silica, 2, 51, American Chem. Soc., Washington D.C. (1994)

[14] Gao XT, Wachs IE, Catal. Today, 51(2), 233 (1999)

[15] Miller JB, Johnston ST, Ko EI, J. Catal., 150(2), 311 (1994)

[16] Gunji T, Kasahara T, Abe Y, J. Sol-Gel Sci. Tech., 13, 975 (1998)

[17] Liu ZF, Crumbaugh GM, Davis RJ, J. Catal., 159(1), 83 (1996)

[18] Ding Z, Zhu HY, Greenfield PF, Lu GQ, J. Colloid Interface Sci., 238(2), 267 (2001)

[19] Anderson C, Bard AJ, J. Phys. Chem. B, 101(14), 2611 (1997)

[20] Tanabe K, Bull. Chem. Soc. Jpn., 47, 1064 (1974)

[21] Brinker CJ, Schere GW, Sol-Gel Science, Structure of Porous Gels, 9, 529, Academic Press, New York (1990)

[22] Brinker CJ, Schere GW, Roth EP, J. Non-Cryst. Solids, 72, 345 (1985)

[23] Kwak CH, Yang JS, Suh TS, Kim HJ, Choi CS, J. Korean Ind. Eng. Chem., 11(4), 402 (2000)

[24] Yang JS, Kwak CH, Suh TS, Choi CS, J. Korean Ind. Eng. Chem., 11(8), 944 (2000)