Fig. 1

rGO morphology and physicochemical characterization. a UV–Visible absorbance spectrum of rGO (70 µg/ml, 265 nm). Inset shows the corresponding rGO suspension photograph. b HRTEM image showing part of the rGO morphology. c Raman spectrum of rGO with the excitation wavelength set to 514.5 nm (Ar ion laser). The C–C sp3 peak of the GO appears at ~1350 cm⁻¹ (D-band) and the sp2 peak at ~1598 cm⁻¹ (G-band). a.u. arbitrary units