Facile synthesis of PdO/SnO2/CuO nanocomposite with enhanced carbon monoxide gas sensing performance at low operating temperature

This study describes a facile strategy for the synthesis of palladium oxide (PdO)/tin oxide (SnO2)/cupric oxide (CuO) nanocomposite with different PdO contents and their application as carbon monoxide (CO) sensing materials. The structure, surface composition and morphology of the materials were scrutinized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The gas sensing properties of all sensors were investigated by exposing them to various concentration of CO gas ranging from 100 to 2000 ppm. The results revealed that the 7%PdO/SnO2/CuO sensor had enhanced sensing response toward CO gas with the appreciable response and recovery times, wide detection range, high repeatability and long-term stability at a low operating temperature of 200 degrees C. Such improved gas sensing performance could be attributed to the catalytic effect of PdO nanoparticles as well as the formation of SnO2/CuO heterojunction.