One-pot synthesis, characterization, and field emission investigations of composites of polypyrrole with graphene oxide, reduced graphene oxide, and graphene nanoribbons

Pyrrole monomer was polymerized by a chemical oxidative route in the presence of graphene oxide (GO), reduced GO (rGO), and graphene nanoribbons (GNR) separately to prepare composites of polypyrrole (PPy) as PPy-GO, PPy-rGO, and PPy-GNR, respectively. The morphological, chemical, and structural characterization of the as-synthesized products was carried out using scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. Field emission studies of the PPy-GO, PPy-rGO, and PPy-GNR emitters were performed at the base pressure of 1 x 10(-8) mbar in a planar "diode" configuration. The turn-on field values, corresponding to an emission current density of 1 mu A/cm(2), are observed to be 1.5, 2.2, and 0.9 V/mu m for the PPy-GO, PPy-rGO, and PPy-GNR emitters, respectively. The maximum emission current density of 2.5 mA/cm(2) is drawn from PPy-GO at an applied electric field of 3.2 V/mu m, 1.2 mA/cm(2) at 3.6 V/mu m from the PPy-rGO, and 8 mA/cm(2) at 2.2 V/mu m from the PPy-GNR emitters. All of the composites exhibit good emission stability over more than 2 h. The results indicate the potential for a facile route for synthesizing composites of conducting polymers and graphene-based materials, with enhanced functionality. (C) 2017 Wiley Periodicals, Inc.