覆載有奈米金屬的中孔二氧化矽材料，在催化、感測器和生化等領域，具有高度應用潛能。因此，其製備方法為近年研究的關注對象之一。目前合成此材料之方法，多數將?燒後的中孔二氧化矽，藉孔璧改質或孔洞吸附等，承載金屬前驅物，最後將其還原。於本研究中，我們將以多氧金屬酸化合物 ( Polyoxometalates, POM ) 為嵌埋式催化劑，光催化還原四氯金酸於二氧化矽薄中。四氯金酸藉由與微胞外的平衡離子交換進入具介觀結構 ( mesostructure ) 二氧化矽中。並且改變模板之鍊長，合成不同晶面間距的二氧化矽材。小角度X光散射( Small Angle X-ray Scattering, SAXS )及穿透式電子顯微鏡 ( Transmission Electron Microscopy, TEM ) 圖像結果指出此二氧化矽薄膜具有二維六角晶形結構 ( 2D hexagonal )。隨著模板碳鍊長增長，其( 10 )晶面間距也增大。合成過程中經紫外─可見光 ( UV-vis) 吸收光譜量測，觀察於540 nm表面電漿共振吸收峰的增長，確認金奈米粒子形成。金離子加入薄膜以及金奈米粒子形成會使二氧化矽薄膜轉變成二維中心矩形結構，長短軸比a/b為1.31；X光繞射 ( X-ray Diffraction, XRD) 結果也證實金奈米粒子生成； 熱重分析 ( Thermogravimetric Analysis, TGA ) 數據估算奈米金與嵌埋POM的二氧化矽之間重量比約等於2.8； TEM圖像顯示金奈米粒徑為1.7 ± 0.2 nm ，緊密堆疊於薄膜通道中，且金奈米子均勻分佈於薄膜內。本研究提供新的合成路徑，製備覆載於中孔二氧化矽薄膜的金奈米粒子，有高均勻且高負載量的特性，且合成過程不需經熱處理。 Nanometal-embedded mesoporous silicas have recently attracted attention due to their potential application in wide range field, such as catalysis, sensing, integrated photonics and biomedical application. Therefore, much research is interested in preparation of these mate-rials. Reduction of metal precursors absorbed on mesopore wall or bound to modified wall of template-removed mesoporous silica was used as main preparation method. In this study, polyoxometalates (POM) were used as immobilized catalyst to photocatalytically reduce chloroauric acid in mesoporous silica. Chloroauric acid ions replace ions in counter anion region between silica wall and surfactant by ion exchange. Different carbon chain length surfactants have also been used to synthesize various d-spacing materials. Results of small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) indicate that the mesostructure of as-synthesized silica thin films are 2D-hexagonal, p6mm. The d-spacing of mesostrucuture increase while the chain length of used surfactant is increased. The 540 nm surface plasmon resonance increasing during photocatalyticall reduction confirms the formation of gold nanoparticles (GNP). Addition of HAuCl4 and formation of GNP result the mesostructure of silica film change to 2D-rectangular structure which a/b is 1.31 ; X-ray Diffraction (XRD) results also verify the formation of GNPs. The weight ratio estimated from thermogravimetric analysis (TGA) is 2.8/1 for gold/silica. TEM images show the nanogolds which have mean diameter 1.7? 0.2 nm pack closely and uniformly in mesostructure. This study provides a novel synthesis route to prepare high and uniform loading nanometal-embedded mesoporous silicas without heat treatment for template removing.
