In situ gold nanoparticle-decorated three-dimensional tin dioxide nanostructures for sensitive and selective gas-sensing detection of volatile organic compounds

Abstract

Sensitive and selective gas sensors for the detection of volatile organic compounds are highly desired. A composite consisting of a specific structure modified with a noble metal catalyst is considered as a promising sensing material candidate. Herein, we present a three-dimensional tin dioxide (SnO₂) nanostructure in situ-decorated with gold nanoparticles (AuNPs) on the surface; this nanostructure exhibited high gas-sensing performance including high response and selectivity towards volatile organic compounds. To achieve high-loading of AuNPs, 3-aminopropyltrimethoxysilane (APTMS) functionalization was conducted on the surface of SnO₂/carbonaceous precursors prior to the AuNPs growth. The vapors of volatile organic compounds, such as acetone, methanol, and hexane, were employed as analytes for gas-sensing measurements. The results show that the SnO₂ nanostructures decorated with dense AuNPs exhibit remarkably better gas-sensing performance as compared to SnO₂ with few AuNPs and pure SnO₂. In addition, gas sensors based on three-dimensional AuNP-decorated-SnO₂ showed high recognition ability towards different analytes in combination with a principal component analysis method, indicating their promising practical application for gas environment monitoring.