Synthesis of flower-like ZnO microstructures for gas sensor applications

In the present work, flower-like ZnO microstructures were used for solid state gas sensor applications. Well-dispersed flower-like ZnO microstructures were synthesized by hydrothermal method. The size of flower-like ZnO microstructures was about 5–7 μm in radius and they were made up of dozen of ZnO nanorods building block units. Gas sensing device was prepared by thick film technology and tested primarily for NO2 gas at different testing temperatures as well as concentrations. Response increased with gas concentration as well as temperature (except 400 °C). Further, it showed response for 10 ppm of NO2 gas at room temperature. The response for NO2 was higher than the CO, ethanol and acetaldehyde at low operating temperatures. These flower-like ZnO microstructures showed some sort of selectivity for NO2 below 300 °C.