Development of doped ZnO nanoparticles for gas sensing application

In this study sol-gel technique was used to prepare Al-, V- and In-doped ZnO. The morphology and microstructure of samples synthesized was characterized by means of different techniques such as X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM). The characterization results indicated that all as-prepared doped samples maintains the same morphology and microstructure of pure ZnO, being composed of nanoparticles having the hexagonal wurtzite structure of zinc oxide. These characteristics were observed also after thermal treatment. However, with incorporation of dopants, the sensing properties were deeply changed. Results of sensing tests have shown as it is possible to decrease the operating temperature compared to pure ZnO-based sensor and obtain sensors with a higher sensitivity and improved selectivity to the target gas by choosing the more appropriate dopant.