Volatile organic compounds (VOCs) represent a broad category of chemical compounds released into the atmosphere by a number of sources (industrial processes and incomplete engine combustion), some occurring naturally (evaporation form landfill sites). The detection and quantification of VOCs thus is crucial for the air quality monitoring. Amongst the nanostructured gas sensing systems, carbonaceous nanomaterials have proved to be promising in the production of high performance chemical sensing due to their electrical and structural properties (high surface area, high chemical and thermal stability and functionalization capability). In the recent years graphene and related materials (GRMs) have been employed in many sensing experiments and they have been exploited for the detection of a widespread range of chemicals, including VOCs [1]. In this framework, reduced graphene oxide (rGO) played as main actor, because of the specific interactions with gas molecules driven by the presence of chemical functionalities in its structure [2]. In this work, we present the characterization as sensing layer of a material named Graphene-like (GL) layers that combines the graphene structure (a defect-free basal plane) with the presence of oxygen functional groups, mainly carboxylic, on the layer edges. GL layers consist in water-stable small graphenic fragments (composed by 3 or 4 stacked graphene layers) able to self-assemble in thin film on surfaces after drying [3,4]. In this work, GL layers were obtained as stable aqueous suspension through two-step strategies starting from a nanostructured carbon black (CB): oxidation/chemical reduction (involving hydrazine as reductant) and oxidation/solvothermal reduction (involving 1-methyl-2- pyrrolidinone, NMP) approaches. In both cases, the oxidation step destroys the CB backbone producing small graphenic fragments and the following reduction step partially restores the graphenic network, improving the electric conductive proprieties of the layers. GL layers were investigated as chemiresistive sensing material for the detection of selected VOCs, namely ethanol and acetone, in ppm levels.
Exploring the performances of graphene-like layers as chemiresistive sensing material for volatile organic compounds (VOCs) detection
V Gargiulo;R Di Capua;M Alfe';
2016
Abstract
Volatile organic compounds (VOCs) represent a broad category of chemical compounds released into the atmosphere by a number of sources (industrial processes and incomplete engine combustion), some occurring naturally (evaporation form landfill sites). The detection and quantification of VOCs thus is crucial for the air quality monitoring. Amongst the nanostructured gas sensing systems, carbonaceous nanomaterials have proved to be promising in the production of high performance chemical sensing due to their electrical and structural properties (high surface area, high chemical and thermal stability and functionalization capability). In the recent years graphene and related materials (GRMs) have been employed in many sensing experiments and they have been exploited for the detection of a widespread range of chemicals, including VOCs [1]. In this framework, reduced graphene oxide (rGO) played as main actor, because of the specific interactions with gas molecules driven by the presence of chemical functionalities in its structure [2]. In this work, we present the characterization as sensing layer of a material named Graphene-like (GL) layers that combines the graphene structure (a defect-free basal plane) with the presence of oxygen functional groups, mainly carboxylic, on the layer edges. GL layers consist in water-stable small graphenic fragments (composed by 3 or 4 stacked graphene layers) able to self-assemble in thin film on surfaces after drying [3,4]. In this work, GL layers were obtained as stable aqueous suspension through two-step strategies starting from a nanostructured carbon black (CB): oxidation/chemical reduction (involving hydrazine as reductant) and oxidation/solvothermal reduction (involving 1-methyl-2- pyrrolidinone, NMP) approaches. In both cases, the oxidation step destroys the CB backbone producing small graphenic fragments and the following reduction step partially restores the graphenic network, improving the electric conductive proprieties of the layers. GL layers were investigated as chemiresistive sensing material for the detection of selected VOCs, namely ethanol and acetone, in ppm levels.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
