Preparation and microstructure control of metal/oxide nano-composite thin films utilizing porous structure of oxide gels

利用氧化物凝胶多孔结构制备金属/氧化物纳米复合薄膜及其微观结构控制

基本信息

批准号：
06650965
负责人：
KOZUKA Hiromitsu
金额：
$ 1.41万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

Silica coating films containing dispersed gold nanoporticles have been prepared by heat-treating the gel films obtained from tetraethoxysilane-water-ethanol-hydrochloric acid-chloroauric acid tetrahydrate solutions. It was found that the size and shape of the gold particles can be controlled by controlling the solution reaction time and amount of water in the starting solutions. In addition, aligned, elongated gold nenoparticles could be precipitated in coating films consisting of fibrous pseudoboehmite particles.Titania film electrodes containing dispersed gold or silver nanoparticles have been prepared by sol-gel method. It was found that photoresponse emerges in visible region when the metal particles are introduced to the titania photoanodes. The effect of the introduction of gold nanoparticles on the photoelectrochemical properties of dye-sensitized titania film photoanodes was also studied. The introduction of gold nanoparticles decreased the dye-induced photoresponse in the visible region, which was, however, found to be less when the overlap of the optical absorption of the gold particles and dyes was larger. This indicates that the dipole-dipole coupling between the gold particles and dye molecules dose exist, enhancing the photochemical processes occurring at the surface of the electrodes.In summary, it has been demonstrated that the size and shape of the metal nanoparticles can be controlled by controlling the microstructure of the gel matrices, where alignment of elongated metal nanoparticles is also possible. Possibility of development of new photoelectrodes with high energy conversion efficiencies was also investigated.

通过对由四乙氧基硅烷-水-乙醇-盐酸-氯金酸四水合物溶液获得的凝胶膜进行热处理，制备了含有分散的金纳米粒子的二氧化硅涂层膜。研究发现，金颗粒的尺寸和形状可以通过控制溶液反应时间和起始溶液中的水量来控制。此外，在由纤维状拟薄水铝石颗粒组成的涂膜中可以沉淀出排列整齐、细长的金纳米颗粒。采用溶胶-凝胶法制备了含有分散的金或银纳米颗粒的二氧化钛薄膜电极。研究发现，当金属颗粒引入二氧化钛光电阳极时，在可见光区域出现光响应。还研究了金纳米颗粒的引入对染料敏化二氧化钛薄膜光阳极光电化学性能的影响。金纳米颗粒的引入降低了可见光区域中染料诱导的光响应，然而，当金颗粒和染料的光吸收重叠较大时，这种光响应会减少。这表明金颗粒和染料分子剂量之间存在偶极-偶极耦合，增强了电极表面发生的光化学过程。总之，已经证明金属纳米颗粒的尺寸和形状可以通过以下方式控制：控制凝胶基质的微观结构，其中细长的金属纳米颗粒的排列也是可能的。还研究了开发具有高能量转换效率的新型光电极的可能性。