During the last decade, due to its excellent electrical, mechanical and thermal properties chemically modified graphene (G) has been extensively studied for many applications, such as polymer composites, energy-related materials, biomedical applications and sensors. In the latter field, the high electrical conductivity of G allowed to explore its gas sensing performance at room temperature, which opens up to the development of ultra-low power consumption gas sensors. We functionalized pure G both via physical and via chemical route. First, we decorated few-layers G powder with niobium oxide (Nb2O5) nanoclusters by magneton sputtering. Two different samples were prepared by changing electrical power of deposition. In the second case, starting from graphene oxide (GO), we functionalized it with three different aza-crown ethers via nucleophilic attack, where the amine groups of an aza-crown ether molecule can easily react with epoxy sites of GO basal plane. All produced 2D hybrid nanocomposites were deeply morphologically, structurally and chemically characterized. Then, they were deposited onto alumina substrates with gold interdigitated electrodes and their sensing properties were investigated vs. different gases, showing good sensing performance vs. ppm concentrations of NO2 and humidity at room temperature. Moreover, the porous scaffold built by the crown ethers GO functionalization enhanced its possible use for cations trapping application, e.g. water filter.
Graphene-based composites for gas sensing and cation trapping applications
V. Guidi;M. Valt;B. Fabbri;A. Gaiardo
2019
Abstract
During the last decade, due to its excellent electrical, mechanical and thermal properties chemically modified graphene (G) has been extensively studied for many applications, such as polymer composites, energy-related materials, biomedical applications and sensors. In the latter field, the high electrical conductivity of G allowed to explore its gas sensing performance at room temperature, which opens up to the development of ultra-low power consumption gas sensors. We functionalized pure G both via physical and via chemical route. First, we decorated few-layers G powder with niobium oxide (Nb2O5) nanoclusters by magneton sputtering. Two different samples were prepared by changing electrical power of deposition. In the second case, starting from graphene oxide (GO), we functionalized it with three different aza-crown ethers via nucleophilic attack, where the amine groups of an aza-crown ether molecule can easily react with epoxy sites of GO basal plane. All produced 2D hybrid nanocomposites were deeply morphologically, structurally and chemically characterized. Then, they were deposited onto alumina substrates with gold interdigitated electrodes and their sensing properties were investigated vs. different gases, showing good sensing performance vs. ppm concentrations of NO2 and humidity at room temperature. Moreover, the porous scaffold built by the crown ethers GO functionalization enhanced its possible use for cations trapping application, e.g. water filter.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
