나노크기의 TiO2/SiO2 입자는 음이온 계면활성제 AOT(sodium bis(2-ethylhexyl) sulfosuccinate)를 사용하여 W/O 마이크로에멀젼에서 TTIP(titanium isopropoxide)와 TEOS(tetraethylorthosilicate)의 가수분해 반응에 의해 제조하였다. 그때 TEOS의 몰분율은 0.1이였다. 나노입자 제조시 W0(H2O/AOT)비에 따른 열적안정성, 표면적, 결정성 및 결정크기 등과 같은 물리적 특성은 TEM, XRD, BET, FT-IR, TGA-DTA 등을 사용하여 분석하였다. 또한 광촉매적 특성을 알아보기 위해 회분식 반응장치를 이용하여 p-니트로페놀의 광분해 활성을 조사하였다. 제조된 TiO2/SiO2 나노입자는 열처리 온도 105 ℃, 300 ℃에서 비결정구조를 가졌으며, 소성온도 800 ℃에서는 TiO2 결정입자 내에 무정형의 SiO2로 인해 열적 안정성이 증가되었고, 여전히 anatase 결정을 유지하였다. 그리고 TiO2/SiO2(90/10) 입자에서 SiO2 결정은 관찰되지 않았다. 제조된 촉매는 대체로 구형이며 아주 균일한 분포를 갖는 것으로 관찰되었다. W0 비가 증가할수록 결정크기는 증가되었고, 표면적은 감소하는 경향을 나타내었다. 또한 p-니트로페놀에 대한 광분해 활성은 순수한 TiO2 보다 TiO2/SiO2(90/10) 촉매가 우수하였다.

Nanosized TiO2/SiO2 particles were prepared by hydrolysis of TTIP (titanium isopropoxide) and TEOT (tetraethylorthosilicate) in sodium bis (2-ethylhexyl)sulfosuccinate (AOT) reverse micelles. The mole fraction of TEOS was 0.1. The physical properties, such as surface area, thermal stability, crystallite size and crystallinity according to W0 ratio have been investigated by TEM, XRD, BET, FT-IR, TGA and DTA. In addition, the photocatalytic degradation of p-nitrophenol has been studied by using batch reactor in order to compare the photocatalytic activity of prepared nanosized TiO2/SiO2 particles. It is shown that the XRD pattern of the particle heat treated at 105 ℃ and 300 ℃ indicates amorphous and the major phase of all the prepared particles were anatase structure. No significant rutile phase was observed although the calcination temperature at 800 ℃ and no peaks SiO2 crystal were also observed for TiO2/SiO2 (90/10). The presence of amorphous SiO2 in TiO2/SiO2 particle enhanced the thermal stability of TiO2 particle resulting in the suppression of the phase transformation from anatase to rutile phase. The crystallite size of prepared particles decreased with decreasing W0 ratio. The surface area increased with_x000D_ decreasing W0 ratio. In addition, TiO2/SiO2 (90/10) particles shows higher photoactivity than that of pure TiO2 particles.

Nanosized TiO2/SiO2 Particles AOT Reverse Micelle W0 Ratio Photocatalytic Degradation of p-nitrophenol

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