EVALUATION OF GAS SENSOR BEHAVIOUR OF SM3+ DOPED TIO2 NANOPARTICLES

Abstract

The Sol–Gel approach is used to synthesize samarium-doped TiO2 nanoparticles (Sm- TiO2 NPs). Research on the structural, morphological and optical properties of TiO2 nanoparticles by XRD, FESEM, TEM, UV, FTIR, and PL was used. The Sm-TiO2 NPs are verified by the XRD profile of anatase, brookite and rutile phase structures. Crystallite size decreases when Sm doped with TiO2 nanoparticles. The external morphologies of the TiO2 nanoparticles in spherically shaped Sm are captured by FESEM. The sample size distribution and polycrystalline composition of the particles have been analyzed using TEM. The EDX spectrum verifies the presence of Ti, O and Sm elements of all the samples. The values have been found to be very close to what has been expected. Sm substitution greatly affected the optical bandgap of TiO2 nanoparticles. It shows that the band gap decreases from 3.64 to 3.61 eV as the concentrations of Sm increases. FTIR confirms the presence of functional groups and Ti–O bonds present in the prepared sample. PL analysis shows the emission for violet range. Using the dip-coating process, a thin film for sensor function is developed. PVDF flat sheet membrane is used as a substrate for sensing material. For various ethanol concentrations with optimized operating temperatures of 303 K, the sensing behaviour of the sensor element is investigated. The very rapid reaction and recovery time of 10 s and 8 s shows that the prepared samples are appropriate for gas sensor applications.