Cozzoli P Davide, Comparelli Roberto, Fanizza Elisabetta, Curri M Lucia, Agostiano Angela, Laub Danièle
Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy.
J Am Chem Soc. 2004 Mar 31;126(12):3868-79. doi: 10.1021/ja0395846.
A novel colloidal approach toward semiconductor/metal nanocomposites is presented. Organic-soluble anatase TiO(2) nanorods are used for the first time to stabilize Ag nanoparticles in optically clear nonpolar solutions in the absence of specific ligands for silver. Metallic silver is generated upon UV illumination of deaerated TiO(2) solutions containing AgNO(3). The Ag nanoparticles can be obtained in different size-morphological regimes as a function of the irradiation time, due to light-induced photofragmentation and ripening processes. A mechanism for the colloidal stabilization of the silver nanoparticles is tentatively suggested, which regards the TiO(2) nanorods as inorganic stabilizers, thus acting in the same manner as conventional surfactant molecules. The proposed photocatalytic approach offers a convenient method for producing TiO(2)/Ag nanocomposite systems with a certain control over the metal particle size without the use of surfactants and/or additives. Stable colloidal TiO(2)-nanorod-stabilized Ag nanoparticles can be potentially available for a number of applications that require "clean" metal surfaces, such as homogeneous organic catalysis, photocatalysis, and sensing devices.
本文提出了一种制备半导体/金属纳米复合材料的新型胶体方法。首次使用有机可溶性锐钛矿型TiO₂纳米棒，在没有银的特定配体的情况下，在光学透明的非极性溶液中稳定Ag纳米颗粒。在含有AgNO₃的脱气TiO₂溶液经紫外线照射后生成金属银。由于光诱导光碎片化和熟化过程，Ag纳米颗粒可以根据照射时间以不同的尺寸形态状态获得。初步提出了一种银纳米颗粒胶体稳定化的机制，该机制将TiO₂纳米棒视为无机稳定剂，其作用方式与传统表面活性剂分子相同。所提出的光催化方法提供了一种方便的方法，用于制备对金属颗粒尺寸有一定控制的TiO₂/Ag纳米复合体系，而无需使用表面活性剂和/或添加剂。稳定的胶体TiO₂纳米棒稳定的Ag纳米颗粒可能可用于许多需要“清洁”金属表面的应用，如均相有机催化、光催化和传感装置。
