Novel Au-activated SnO2@Fe2O3 hetero-alternated multilayer nanosheets with enhanced low-concentration acetone detection

Abstract

Au nanoparticles-loaded SnO2 @Fe2O3 multilayer nanosheets (A-SnO2 @Fe2O3 MNSs) with flowerlike appearance and porous feature have been successfully synthesized via a self-template strategy, followed by a Fe2O3-growth and Au-loaded process. The detailed microstructural characterizations confirm that A-SnO2 @Fe2O3 MNSs, besides the loaded Au nanoparticles, are constructed of hetero-alternated Fe2O3/SnO2 sublayers, which are further subdivided into two kinds of primary building blocks, including Fe2O3 nanorods and SnO2 nanoparticles. Benefiting from distinctive structural merits of permeable but interconnected hetero multilayers, A-SnO2 @Fe2O3 MNSs can hold a high surface area and effective gas diffusion during the gas adsorption and desorption process. When used as the sensing materials for acetone detection, A-SnO2 @Fe2O3 MNSs exhibit higher sensitivity and faster response/recovery speed to low-concentration acetone compared with the unloaded components. The promotion of acetone sensing performance is attributed to the dramatic sensitization of the loaded Au nanoparticles.