Electrochemical synthesis of carbon fluorooxide nanoparticles from 3C-SiC substrates

Chemical nature of products, formed during electrochemical dissolution of polycrystalline 3C-SiC substrate in HF:ethanol mixture, was studied by means of FTIR spectroscopy, temperature-programmed desorption mass spectrometry (TPD-MS), 1H, 13C, and 19F NMR (solution as well as MAS), XPS, AFM, and other characterization methods. Simultaneous formation of two major products, porous SiC and carbon fluorooxide (CFO) nanoparticles (NPs) with sizes of 1–10 nm, is described. CFO NPs easily dissolve in polar organic solvents (ethanol, CH2Cl2, etc.); their solutions demonstrate intense yellowish-green photoluminescence under UV excitation. A model of the CFO chemical structure based on relatively small graphene domains interconnected with partially fluorinated hydrocarbon groups and terminated by carboxylic acid (−CO2H), ethyl ester (−CO2C2H5), perfluorinated functional groups, and polycarboxylated alkyl chains is proposed. Presence of carboxylates allows easy functionalization of the CFO NPs via amide chemistry. In particular, grafting of octadecyl groups makes CFO NPs soluble in hydrocarbons.The authors are grateful to IRSES European Project “Porous Silicon Carbide as a support for Co metal nanoparticles in Fischer−Tropsch synthesis” (proposal number: 319013) and Visby Swedish institute project 00814/2011 “Surface-Assisted Laser Desorption Ionization of biomolecules on modified porous Silicon/Silicon Carbide for their better analysis” for partial financial support.Peer Reviewe