Effect of Cr on ZrO2 nanostructures for gas sensing investigation

This study deals with the synthesis, characterization and gas sensing interrogations of pure and Cr (5 and 15%) doped ZrO2. The conventional precipitation route is committed for the synthesis of the pure and Cr-doped ZrO2 powder and the films were formulated by drop casting mode by exploiting ZrOCl2·8H2O as precursor, CrO3 as doping agent and NH4OH as stabilizing agent. The structural properties, optical properties and electrical properties of the handled samples were anatomized by X-ray diffraction (XRD), scanning electron microscopy, ultraviolet–differential reflectance spectroscopy (UV-DRS) spectroscopy, photoluminescence (PL) studies and current–voltage (I–V) measurement. The structure and size of the crystal were resolved by XRD. The uniform spherical-like morphology of the particles was favoured by SEM investigation. The bandgap of the materials was reckoned by UV-DRS report. The occupancy of oxygen vacancies in the samples was conceded by PL studies. The ohmic contact of the samples with the electrodes has been professed by I–V measurements. The gas sensing competency of the drop casted films were monitored by the exposure of the different concentrations of reducing gases like ammonia, acetone, ethanol, formaldehyde and xylene. The output data render that all the processed samples exhibits a peak response towards ammonia gas, exclusively 15% of Cr-doped ZrO2 sensor shows an utmost gas response of about 48%, excellent response time and recovery time of about 68 and 72 s, respectively, among other samples. Thus, the fusion of Cr stimulates the gas sensing proficiency of ZrO2.