Evaluation of ZnO nanoparticles and study of ZnO–TiO2 composites for lead free humidity sensors

This paper deals with synthesis of ZnO nanoparticles through two different baths: Ammonium zincate bath and sodium zincate bath. Synthesized ZnO nanoparticles were characterized by means of TG/DTA, FTIR, UV-vis, XRD, and FESEM. ZnO nanoparticles were then mixed with commercial TiO2 in various percentage (3 wt%, 5 wt%, 10 wt%) and lead free thick films were prepared. XRD analysis for the films reveals presence of ZnO, Zn2TiO4 and TiO2. SEM analyses show that presence of larger amount of Zn2TiO4 and higher surface to volume ratio in 10 wt% TiO2 added ZnO films are the primary reason for higher sensitivity.