Ordered mesoporous Ag-doped TiO2/SnO2 nanocomposite based highly sensitive and selective VOC sensors

Abstract

Hybrid mesoporous metal oxides show promising attributes in the field of relative gas sensors due to the combined opportunities provided by the high specific surface area and framework components. In this study, we present the synthesis of Ag-doped ordered mesoporous tin(IV) oxide–titanium(IV) oxide nanohybrids using a sequential combination of a wet impregnation and nanocasting process and demonstrate the response by exposing the mesoporous nanohybrids to ethanol gas. HRTEM and N₂ adsorption–desorption results indicate that the nanohybrids prepared by nanocasting of SBA-15 as the hard template possess an ordered mesoporous structure and high surface area. It was also observed that the mesoporous Ag-(TiO₂/SnO₂) shows excellent response towards ethanol with concentrations ranging from 1 ppm to 500 ppm. Besides, the nanohybrid mesoporous sensor shows high selectivity towards other volatile organic compounds (VOCs) including acetone, methanol, isopropanol, benzyl alcohol and ethyl acetate. All the results indicated that the nanocast mesoporous Ag-(TiO₂/SnO₂) nanohybrids have great potential for applications in designing high performance practical ethanol sensors.