• E HEMALATHA

Articles written in Bulletin of Materials Science

• Synthesis of ZrO$_2$ nanostructure for gas sensing application

ZrO$_2$ nanopowder has been synthesized by the conventional precipitation method for gas-sensing application. The synthesized powder was dropcast and subsequently annealed at 100$^{\circ}$C. The drop-casted film has been subjected to X-ray diffraction analysis, scanning electron microscopy, ultraviolet–visible diffuse reflectance spectroscopy, photoluminescence study and $I –V$ measurement in order to observe its structural, morphological, optical and electrical properties. The gas sensing measurement has been performed for the thus prepared ZrO$_2$ film by an exposure to different reducing gases(ammonia, ethanol, formaldehyde, acetone and xylene) at different temperatures for various gas concentrations. It has been observed that the film shows a better response towards ammonia (about 18%) compared to all other gases due to faster diffusion. Also, a quick response and recovery time have been found as 70 and 70 s, respectively, for ammonia.

• Effect of Cr on ZrO$_2$ nanostructures for gas sensing investigation

This study deals with the synthesis, characterization and gas sensing interrogations of pure and Cr (5 and 15%) doped ZrO$_2$. The conventional precipitation route is committed for the synthesis of the pure and Cr-doped ZrO$_2$ powder and the films were formulated by drop casting mode by exploiting ZrOCl$_2$.8H$_2$O as precursor, CrO$_3$ as doping agent and NH$_4$OH as stabilizing agent. The structural properties, optical properties and electrical properties of the handledsamples 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 datarender that all the processed samples exhibits a peak response towards ammonia gas, exclusively 15% of Cr-doped ZrO$_2$ sensor shows an utmost gas response of about 48%, excellent response time and recovery time of about 68 and 72s,respectively, among other samples. Thus, the fusion of Cr stimulates the gas sensing proficiency of ZrO$_2$.

• Bulletin of Materials Science

Volume 45, 2022
All articles
Continuous Article Publishing mode

• Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020