Highly sensitive NO2 gas sensor based on zinc oxide/copper oxide hybrid-nanostructures

This work explains a facile approach to fabricate hybrid-nanostructure based gas sensor. The prefabricated sensor chip with microheaters was used to grow ZnO/CuO hybrid-nanostructures directly on top of electrodes using hydrothermal reaction at low temperature (<;95 °C). It was found that controlling the precursor concentration and growth time were the keys to minimize the damage on the base structures. As a gas sensor, the fabricated device based on ZnO/CuO hybrid-nanostructures was tested and shown to enhance the response from 2500 to 7100 % as compared to the ZnO nanowire-based device upon the exposure to 20 ppm of NO₂ gas at 250 °C.