Spontaneous reduction and dispersion of graphene nano-platelets with in situ synthesized hydrazine assisted by hexamethyldisilazane

The environmentally friendly reduction and a solution processability of chemically modified graphene nanosheets are most important for their applications. Here we report for the first time that in situ synthesis of hydrazine and spontaneous reduction of graphene oxide (GO) in solution can be achieved just by addition of hexamethyldisilazane (HMDS) and hydrogen peroxide into the GO suspension and followed by step-wise heating. We also demonstrated that GO functionalized with carbonyl groups can be used as an alternative to ketone molecules as a catalyst in a typical reaction cycle for hydrazine synthesis by identifying intermediate azine structures. The successful synthesis of hydrazine and spontaneous reduction of GO at 100 °C was confirmed by measuring X-ray photoelectron spectra and Fourier transform infrared spectra of RGO powder and UV absorbance spectra of RGO solution. Moreover, trimethylsilanol molecules from HMDS contributed to a stable colloidal RGO suspension even in ethanol. In situ synthesis of hydrazine molecules in GO suspension provides a new environmentally friendly process for application of chemically modified graphene in electronics and composites.