Growth of close-packed crystalline polypyrrole on graphene oxide via in situ polymerization of two-monomer-connected precursors

Synthesis of a two-dimensional (2D) highly crystalline composite, P(Py:BPDSA:Py)-GO, from the growth of a close-packed polymer crystal, P(Py:BPDSA:Py), on graphene oxide (GO) sheets via in situ polymerization of two-monomer-connected precursors (TMCPs, Py:BPDSA:Py), in which two pyrrole (Py) molecules are linked through a connector (4,4'-biphenyldisulfonic acid) (BPDSA), is reported. When the TMCP is polymerized on GO, it leads to an exceptionally ordered structure determined by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) studies. X-ray crystallography of the composite shows crystalline peaks with d spacings in the [100] direction. Transmission electron microscopy (TEM) analysis indicates that the composite has a face-centered cubic (FCC) crystal structure. Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) show that this composite with a well-defined nanostructure was successfully synthesized. Nitrogen adsorption-desorption isotherms show that this composite, P(Py:BPDSA:Py)-GO, has an improved specific surface area (71 m² g^-1) compared to that of P(Py:BPDSA:Py) (3.1 m² g^-1). The electrochemical properties of the composite studied by cyclic voltammetry indicates a specific capacitance of 480 F g^-1 without an additional conducting material such as carbon black, suggesting its use as a pseudocapacitor.