Simultaneous reduction and surface functionalization of graphene oxide for highly conductive and water dispersible graphene derivatives

A simple and effective preparation method for the simultaneous reduction and functionalization of graphene oxide (rGO) by 2,4-diamino benzene sulfonic acid has been developed. The derivatives exhibit excellent conductivity and high dispersibility in various solvents. The successful preparation of rGO and the presence of the sulfonated aromatic diamine on rGO surface has been confirmed by infrared and X-ray photoelectron spectroscopy, while, the analysis by micro-Raman spectroscopy indicated that the reduction/functionalization alters the lattice structure of GO by the increment the defect density when the 2,4-diamino benzene sulfonic acid is used. Moreover, the study of the dried products by X-ray diffraction spectroscopy suggested the turbostratic restacking of the exfoliated rGO into graphite-like nanostructures. The obtained derivative of simultaneous reduction and functionalization of GO was used for the preparation of highly conductive water-based gravure ink, which in turn, was successfully applied in printing on various flexible substrates, demonstrating its great potentiality in graphene-based flexible and printed electronics applications.