Synthesis of SnO2/ ZnO Core- Shell Nanocomposites via Sonochemical Method and Evaluation of their Gas Sensing Properties

In this paper, SnO2/ZnO core - shell nanocomposites were synthesized via sonochemical processing. To achieve this, ZnO nanoparticles were prepared by ultrasonic method. In the next stage, the core-shell nanocomposites in the presence of ZnO particles (prepared in the previous step) and adding precursor SnCl4.5H2O was prepared by ultrasonic. After synthesizing the nanocomposites, their properties were studied by XRD, TG-DTA and TEM analyses. The synthesized SnO2/ZnO core - shell nanocomposites have amorphous structure that can be changed to crystalline structure after calcination at 650 C for 1 hour. Also, the gas sensing characteristics of SnO2/ZnO core- shell nanocomposite was studied. For evaluating the gas sensing properties, the synthesized particles were prepared by pressing the powder into pills and gas sensing test was performed with respect to the various gases such as methanol, CO, and H2. Due to the unique properties of the core - shell semiconductor particles in the mechanism of charge separation, the gas sensing properties of core - shell particles are higher than those of pure oxides.