Highly sensitive detection of acetone using mesoporous In2O3 nanospheres decorated with Au nanoparticles

Abstract

Surface modification with noble metal is considered as an effective strategy to enhance sensing performance of metal oxide-based gas sensors. In this work, mesoporous In2O3 nanospheres decorated with gold nanoparticles (Au NPs) have been successfully synthesized by a two-step approach including a facile hydrothermal reaction and subsequent in situ reducing process. Various techniques were employed for the characterization of the structure and morphology of as-obtained Au/In2O3 nanocomposites. The results reveal that Au NPs with average diameters of 3–5nm are uniformly deposited on the surface of mesoporous In2O3 nanospheres with a size range of 100–200nm, specific surface area of 40.3m2/g, and average pore size of 5nm. Importantly, the mesoporous structure, large specific surface area, and catalytic effect of Au NPs endow the Au/In2O3 nanocomposites with highly sensitive performance for acetone detection. The response value to 10ppm acetone is about 53.08 at an operating temperature of 320°C, and the response and recovery time are 4 and 9s, respectively. The probable enhancing mechanism of as-prepared Au/In2O3 nanocomposites is discussed as well. It is expected that Au NPs-decorated mesoporous In2O3 nanosphere with excellent sensing performance is a promising functional material to actual application in monitoring and detecting acetone.