Antonino Biagio Carbonaro1,Daniele Fumagalli2,Valentina Greco1,Antonino Gulino1,Valentina Pifferi2,Luigi Falciola2,Alessandro Giuffrida1
University of Catania, Department of Chemical Sciences1,University of Milan-La Statale2
Antonino Biagio Carbonaro1,Daniele Fumagalli2,Valentina Greco1,Antonino Gulino1,Valentina Pifferi2,Luigi Falciola2,Alessandro Giuffrida1
University of Catania, Department of Chemical Sciences1,University of Milan-La Statale2
Recently, three-dimensional porous graphene architectures, such as hydrogels and aerogels, have received increasing attention in the scientific literature due to their unique structural, chemical and physical properties. Combined with the well-studied brilliant properties of graphene-based materials, 3D graphene structures find applications in bioelectronics, sensing and energy storage. The meso- and macroporous structure of hydrogels and aerogels allows to overcome some limitations of 2D graphene materials, such as the re-stacking of monolayers, which confers unique properties due to the high active surface area of well-defined 3D graphene architectures. Most applications of graphene hydrogels and aerogels are based on the interaction between the porous carbon structure with molecular species, in the gas or liquid phase. In this context, functionalization strategies that allow the control of surface speciation would be highly welcomed. Functionalization methods for graphene hydrogels include non-covalent approaches where the guest species are physisorbed onto the porous structure during the gelation process. However, this approach can have many disadvantages, such as molecule slippage, and they are difficult to control compared to a covalent functionalization strategy. Keep this in mind, in this work we would like to shed light on the chemical behaviour of graphene hydrogels; in particular, according to the flow chemistry concepts, we propose a facile covalent functionalization strategy through Diazonium Salts Chemistry. The samples were extensively characterized by micro-Raman and ATR-FTIR spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and BET. In addition, the electrochemical performances of the 3D porous graphene hydrogel and aerogel structures were investigated by Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Electrochemical Impedance Spectroscopy (EIS), focusing on the electrochemical sensing properties of the 3D self-standing structures.