rGO/In2O3 heterostructures based gas sensor for efficient ppb-level n-butanol detection

The real-time and effective detection of n-butanol gas is particularly important in production and daily life due to its flammability, toxicity, and potential hazards to the environment. This article reports the preparation of hollow indium oxide spheres and rGO/In2O3 composites through a simple hydrothermal and subsequent heat treatment method. Test results indicate that the gas sensitivity of n-butanol can be significantly improved through rGO composites. The prepared hollow indium oxide spheres are composed of nanosheets with a diameter of probably 500 nm. After combination by rGO, the specific surface area and the proportion of adsorbed oxygen of the material are increased, both of which are advantageous for enhancing gas sensitivity abilities. At the optimum operating temperature of 160 oC, the response value of rGO/In2O3 complex sensor is 51 to 50 ppm of n-butanol, which is 3.6 times the response of pure In2O3. Gas sensors composed of rGO/In2O3 exhibit ultra-fast response time and low detection limit. Even for ppb grade (100 ppb) n-butanol gas, the response value is still 2.3. These characteristics make rGO/In2O3 a promising material for the preparation of high-performance n-butanol gas sensors. Besides, the gas-sensitive mechanism of the enhanced n-butanol sensing performances is also analyzed.