Rapid acetone detection using indium loaded WO3/SnO2 nanohybrid sensor

Growth of multifunctional nanohybrids with ordered porous structures is a much sought aspect for real time applications of mesoporous materials in detecting trace biomarkers in exhaled breathe. Here, we demonstrate the utilization of mesoporous silica (KIT-6) exhibiting 3-D porous structure as hard template for the development of Indium loaded WO3-SnO2 ordered nanohybrids by nanocasting approach. The negative replicated structure of In/WO3-SnO2 was tested for selective trace detection of important Volatile Organic Compounds (VOCs) present in human breathe (acetone, ethanol, formaldehyde, trimethylamine and 1,3,5 trimethylbenzene). The sensing results illustrate that In/WO3-SnO2 (2 wt% In, R-a/R-g = 66.5) showed 2.12 and 3.16 times better response than pure WO3-SnO2 (R-a/R-g = 31.3) and In/SnO2 (R-a/R-g = 21.1) nanocomposite for 50 ppm acetone gas at a relatively lower operating temperature. The hybrid nanocomposite In(2)/WO3-SnO2 was able to detect 1 ppm trace acetone gas with a significant rapid response (4 s) and recovery time (2 s) along with linear response, high stability, good reversibility and excellent selectivity. The present study reported rapid detection of important VOCs in a dynamic range from 1-500 ppm and has potential application in designing a futuristic handheld nanostructured device with enhanced gas-sensing performance.