Liquid petroleum gas sensing performance enhanced by CuO modification of nanocrystalline ZnO-TiO₂

Nanocrystalline ZnO-TiO₂ (with molar ratios 9:1, 7:3, 1:1, 3:7 and 1:9) were successfully synthesized by hydrothermal method. Synthesized materials were examined with the help of X-ray diffraction and transmission electron microscope. Liquid petroleum gas sensing characteristics of the ZnO-TiO₂ films were investigated at different operating temperatures. The ZnO-TiO₂ thick film (with 1:1 molar ratio) exhibited good response toward liquid petroleum gas as compared to other investigated compositions. Further, liquid petroleum gas sensing characteristics of CuO modified ZnO-TiO₂ thick films were investigated. 0.2 M CuO modified ZnO-TiO₂ thick film exhibited excellent liquid petroleum gas sensing characteristics such as higher response (~ 1637.49 at 185 °C) with quick response time (~30 s), low recovery time (~70 s), excellent repeatability and stability at low operating temperature.