Highly Reproducible and Reliable Methanol Sensor Based on Hydrothermally Grown TiO2 Nanoparticles

Abstract

In the present paper, TiO2 nanoparticles were synthesized through low cost hydrothermal method at 150°C. Structural, morphological and optical properties of the grown materials were characterized through X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Raman Spectroscopy, and Photoluminescence spectroscopy, respectively. X-ray diffraction confirms the anatase phase with average crystalline size of 6.8 nm. Non-uniform particles having numerous pores with large number of active sites offered superior capability to detect methanol even at lower concentrations. Band gap of the material were found to be 3.4 eV. TiO2 nanoparticles in planner structure were investigated towards methanol (1-100 ppm) at the temperature ranging from (25-150°C). Sensor was found to be maximum responsive with response magnitude of 85% at 100°C and 47% at room temperature towards 100 ppm of methanol. At 1 ppm of methanol, sensor response was found to be 20%. Sensor response towards methanol was correlated with the surface state of nanoparticles with HOMO-LUMO energy.