Carbon Quantum Dot-Functionalized Aerogels for NO₂ Gas Sensing

Abstract

Silica aerogels functionalized with strongly fluorescent carbon quantum dots were first prepared and used for simple, sensitive, and selective sensing of NO₂ gas. In the presence of ethanol, homemade silica aerogels with a large specific surface area of 801.17 m²/g were functionalized with branched polyethylenimine-capped quantum dots (BPEI-CQDs) with fluorescence quantum yield higher than 40%. The prepared porous CQD-aerogel hybrid material could maintain its excellent fluorescence (FL) activity in its solid state. The FL of CQD-aerogel hybrid material could be selectively and sensitively quenched by NO₂ gas, suggesting a promising application of the new FL-functionalized aerogels in gas sensing