Sep 3, 2009
Organic protection keeps as-prepared nanorods intact
Metal oxides such as TiO2 have been investigated extensively due to their special semiconducting properties and applications in photovoltaic cells, sensors and photocatalysis. Fabrication of TiO2 into one-dimensional nanostructures can dramatically increase the material's effective surfaces and manipulate its size and shape-related properties. During the past decade, many efforts have been made to synthesize one-dimensional nanostructures using metal salts or complexes as precursors.
The assembly of nanoparticles using one-dimensional templates such as anodic aluminum oxide (AAO) has been cited as a possible fabrication route. However, the as-prepared one-dimensional nanostructures composed of the pure nanoparticles are often broken when the template is removed due to the fragile nature of the deposit.
To safeguard the nanostructures, researchers in China have come up with an organic protection assisted template method of fabricating of TiO2 nanorods from TiO2 nanoparticles. After depositing perylene around the wall of the channels in the porous alumina membranes, subsequent implantation of TiO2 nanoparticles resulted in TiO2/perylene composite nanorods, which replicated the morphology of the templates completely. The protective layer of perylene can be removed using a calcination process to allow recovery of the TiO2 nanorods.
The group supposes that the organic layer is able to protect the TiO2 rods from damage during the removal of the templates by alkaline etching. Such an organic protection assisted template method offers a new approach to fabricating one-dimensional nanostructures from nanoparticles.
The researchers presented their work in Nanotechnology.
About the author
Zhixun Luo and Yi Zhen are PhD students in Prof. Jiannian Yao's group at the Institute of Chemistry, Chinese Academy of Sciences. Aidong Peng is a researcher in Yao's group. Wensheng Yang is a full professor of physical chemistry at the Jilin University. Prof. Yao's current research interests include novel photo-functional materials, nanochemistry and the construction of novel nanostructures, low-dimensional organic materials and photochromic inorganic and organic/inorganic hybrid materials.