Reduction of graphene oxide through a green and metal-free approach using formic acid

The present work reports on the production of reduced graphene oxide (GO) by the chemical reduction of GO using formic acid. The process involved is simple, environmentally friendly, low cost and metal free. The structural and electrical characterization ascertains that the quality of the material improves with the time of reduction. To compare the effect of reduction time, three samples are prepared for 18,24 and 30 h respectively. The samples produced are characterized to confirm the reduction of GO and formation of reduced GO (FRGO) by high-resolution transmission electron microscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction pattern, ultraviolet visible spectroscopy and Raman spectroscopy. Among the three samples, FRGO-3 prepared for reduction time of 30 h shows a good crystalline behavior and the highest electrical conductivity (11.859 S/cm) at room temperature. This value is comparable with other reported values. Further, from thermo-gravimetric analysis reasonable thermal stability for FRGO-3 is observed in the temperature range 400-800 degrees C. Based on the above observations a mechanism of reduction from GO to reduced GO by formic acid (FRGO) is proposed. (C) 2013 Elsevier B.V. All rights reserved.