Performance of Ni-doped ZnO nanoparticles towards CH3-CO-CH3 sensing

Early detection of volatile organic compounds like acetone (CH3-CO-CH3) demands a prior work for a healthy environment as their presence with higher concentration negatively impacts health, causing serious diseases. To fabricate a VOC gas sensor operating at low temperature with improved sensitivity, Ni-doped ZnO nanoparticles (NZNPs) were prepared by the sol-gel auto combustion method by taking zinc nitrate hexahydrate and nickel nitrate hexahydrate as starting materials with very low cost. X-ray diffraction (XRD) patterns reveals polycrystalline nature of the samples with hexagonal wurtzite structure. The samples are found to be free from impurity phases with average crystallite size in the nanometer range, indicating positive signs towards improved gas sensing properties. Scanning electron microscopy (SEM) studied surface morphology, which reveals small grain size with a porous arrangement. Sensing properties of NZNPs were carried out for the detection of acetone both at room temperature (RT) and 100°C. It was observed that NZNPs show better sensitivity with lower response time(~18sec.) and recovery time(~8sec.) towards acetone at the optimal operating temperature of 100°C, indicating its applicability in low-temperature operating sensing devices.