Aidin Lak - Department of Materials Science and Engineering and ۲Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P. O. Box ۱۱۳۶۵-۹۴۶۶, Azadi Avenue, Tehran, Iran
A Simchi
Z. Ali. Nemati

Efficient degradatation of water pollutants are the current concern of many efforts worldwide. Among the various conventional and advanced methods such as Advanced Oxidation Processes (AOPs), semiconductor-assisted photocatalysis has attracted great attention for its direct conversion of pollutants into harmless eco-friendly components in waste waters [1, 2]. Here, ZnO and TiO2 are the most promising candidates for usage due to their interesting properties including photo-stability, resistance to photo-corrosion, photo-sensivity and nontoxitic [3, 4]. In order to improve the properties of these semiconductors, synthesizing of coupled and capped nanostructures have been proposed. It has been reported that the efficiency of photo-induced charge separation can be improved by coupling two semicondutors with different energy levels [5]. This paper reports the synthesis of TiO2-capped ZnO nanoparticles through a two-step chemical method. The photocatalytic decolorization of Methylene blue (MB) by the core/shell nanostructure is shown and compared with hydrothermally synthesized ZnO and TiO2 (P-25, Degussa) nanoparticles