Facile synthesis of highly conducting polypyrrole and reduced graphene oxide nanocomposites for low-turn-on electron field emitters

Abstract

A novel one-pot synthesis of polypyrrole (PPy)/reduced graphene oxide (r-GO) nanocomposites with the aim of assessing their potential as a cold cathode material is reported. r-GO was prepared by a modified Hummers and Offeman method. The nanocomposites were characterized by transmission electron microscopy, field-emission scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy and Raman spectroscopy. The isothermal DC conductivity of PPy was found to increase by four orders of magnitude (2160 S/m) on r-GO doping. The nanocomposites were explored for field emission, and the results fitted well to the Fowler–Nordheim model of emission. The maximum values of the current density (26 μA/cm2) and the field enhancement factor (β = 8.0 × 104) were obtained for PPy/r-GO (10%) for a very small turn-on field (1.3 V/μm), and are much higher than those of any other polymer-based nanocomposite.