Synthesis and enhanced light absorption of alumina matrix nanocomposites containing multilayer oxide nanorods and silver nanoparticles

• Published in: Materials research bulletin 2011-11, Vol.46 (11), p.1828-1836
• Main Authors: Gan, Yong X., Zeng, Xianwu, Su, Lusheng, Yang, Lu, Gan, Bo J., Zhang, Lihua
• Format: Article
• Language: English
• Subjects: A. Metals; A. Oxides; ABSORPTION; ALUMINIUM OXIDES; B. Chemical synthesis; C. Electron microscopy; chemical synthesis; COMPOSITE MATERIALS; D. Optical properties; DEPOSITION; ELECTRON MICROSCOPY; functional nanomaterials; HEAT TREATMENTS; HYDROLYSIS; MATERIALS SCIENCE; OPTICAL PROPERTIES; OXIDES; PLASMONS; PYROLYSIS; SCANNING ELECTRON MICROSCOPY; SILVER; SYNTHESIS; THICKNESS; TRANSMISSION ELECTRON MICROSCOPY; VISIBLE RADIATION; WAVELENGTHS
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2011.07.050

[Display omitted] ► Multilayer oxide nanorods (nanocables) were obtained via chemical processing. ► Ag nanoparticles were deposited between the core and shell layers of the nanorods. ► The structure and composition of the nanorods were analyzed by SEM and TEM. ► CoO nanorods and Ag nanoparticles enhance light absorption of the nanocomposites. In this paper, multilayer oxide nanorods were deposited in the nanopores of anodic aluminum oxide (AAO) via solution infiltration followed by heat treatment. The nanorods have a core–shell structure. First, the shell (nanotube) with the thickness of about 40 nm was made of TiO 2 through the hydrolysis of (NH 4) 2TiF 6. Second, silver nanoparticles with the diameter of about 3 nm were added into the TiO 2 layer through thermal decomposition of AgNO 3 at elevated temperatures. Then, cylindrical cores (nanorods) of CoO and ZnO with 200 nm diameter were prepared, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and composition of the nanorods. UV–vis light absorption measurements in the wavelength range from 350 to 1000 nm were performed to study the effect of nanorod and nanoparticle addition on the light absorption property of the alumina nanocomposites. It is found that CoO nanorods increase the light absorption of the alumina matrix composite in the wavelength range from 500 nm to 800 nm, but the TiO 2 shell does not increase the light absorption much. The ZnO nanorods do not change the light absorption either. However, the addition of silver nanoparticles significantly enhances light absorption of both AAO/TiO 2/Ag/CoO and AAO/TiO 2/Ag/ZnO nanocomposites. This increase in the visible light absorption reveals that there exists surface plasmon around the fine silver nanoparticles in the nanorods.