Synthesis and characterization of ZnO/CuO nanocomposite for humidity sensor application

Metal oxide nanomaterials shows variety of applications in the field of optoelectronics, semiconductors, catalysis, coatings, solar cells, ceramics, spintronic, biological and sensors. Present paper deals with ZnO/CuO nanocomposite material synthesis, characterization and humidity sensor application. Novelty of this work is to know the high sensitivity of two conjugated n and p type semiconductor metal oxide nanocomposite at various temperatures. Nanocomposite materials are synthesized by microwave-assisted method with the help of room temperature ionic liquid (RTIL). Zinc acetate, Copper acetate, Sodium hydroxide and 1-butyl-3-methyl-imidazolium-tetrafluoroborate ([BMIM]BF4) were used as initial precursors. The obtained nanocomposite materials were annealed at different temperatures such as 500 °C, 600 °C, 700 °C and 800 °C. These annealed nanocomposite materials have been characterized by X-ray diffractometer (XRD), Particle size analyzer (PSA), Scanning electron microscope (SEM), Energy dispersive x-ray spectrometer (EDS) and Thermo gravimetric and differential thermal analyzer (TG/DTA) for analyze crystal structure, average particle size, surface morphology, elemental analysis and weight loss respectively. The humidity sensor application was predicted by controlled humidity chamber, hygrometer and digital multi meter. The resistance of the sensing element measured with respect to relative humidity from 10% to 98%. The sensitivity of the nanocomposite material increased from 1.7 % to 2.3 % along with increasing of annealing temperature 500 °C to 800 °C. ZnO/CuO nanocomposite annealed at 800 °C shows high sensitivity means it is also having good response and recovery times.