Carbonaceous nanosheets decorated with amino-functionalized organosilica nanoparticles have been synthesized by a direct pyrolysis of betaine at 400 degrees C in air, followed by a simple surface treatment with ([3-(2-aminoethylamino) propyl] trimethoxysilane under reflux conditions. Both pristine and organosilica modified carbon nanosheets (OMCNs), were characterized by Fourier-transform infrared (FTIR), Raman, and electron paramagnetic resonance (EPR) spectroscopies, transmission electron microscopy and thermal analysis methods. The experimental data reveal a dramatic increase in the number of radical centers on the surface of the developed OMCN hybrid. The organosilica nanoparticles, ranging in size between 3 and 15 nm, are spherical and homogenously anchored on the surface of carbon nanosheets. The formation of C-O-Si bridges between carbon sheets and the organosilica nanoparticles has been supported by FTIR and EPR. These nanoparticles are bound to the nanosheet surface together with individual functional organosilane groups at a spacing of about 4 angstrom distance. The final hybrid is the complex nanosystem composed of 2D carbon nanosheets, spherical organosilica nanoparticles and immobilized amino organosilane molecules. (C) 2012 Elsevier B. V. All rights reserved.