Reduced Graphene Oxide@Bimodal TiO<sub>2</sub> Nanocomposites as an Efficacious Console for Room Temperature <i>n</i>-Butanol Gas Sensing
Nileshkumar M. Pardeshi, Rahul Suresh Ghuge, Priyanka N. Birla, Ratna Chauhan, Shyamal P. Bhalekar, Manish Shinde, Yuvaraj Sivalingam, Rajendra D. Kale, Sunit Rane
Abstract
Metal oxide nanomaterials possess an exceptional physical and chemical behavior apposite for gas-sensing applications. Among them, titanium dioxide (TiO 2 ) is a promising, robust, and economical material, and when paired with two-dimensional (2D) materials such as reduced graphene oxide (rGO), the resultant composite system is promoted to an interesting gas-sensing candidate. Properties of rGO- and TiO 2 -based nanocomposites depend on the size and shape of TiO 2 nanoparticles and the weight percentage (wt %) ratio of rGO/TiO 2 . Herein, the preparation of rGO@bimodal TiO 2 nanocomposites (hereafter referred to as G@TiO 2 ) by the conventional hydrothermal method having different wt % (1, 2.5, 5, and 10) of rGO with bimodal TiO 2 nanoparticles is reported. Structural, optical, morphological, and microstructural characterizations of the prepared nanocomposites revealed the generation of elongated submicron particles and nanorods of bimodal TiO 2 in the G@TiO 2 samples. The gas sensors based on the prepared materials were fabricated to evaluate their gas-sensing properties. The comparative analysis illustrated that the sensor based on 2.5%G@TiO 2 presented the highest sensitivity and selectivity to n -butanol at room temperature (25 °C). Furthermore, supplemental investigation on n -butanol adsorption properties of all sensors was carried out using a scanning Kelvin probe (SKP) technique, which further corroborated the exceptional n -butanol adsorption (>2 times) for the 2.5%G@TiO 2 surface at room temperature.