Optoelectrical and photoluminescence quenching properties of poly(N-vinyl carbazole)-polypyrrole/reduced graphene oxide nanocomposites

Abstract

Dodecylbenzenesulfonic acid (DBSA) doped poly(N-vinyl carbazole)/polypyrrole (PNVC-PPy) was decorated on various concentrations of reduced graphene oxide (RGO) by facial in-situ chemical synthesis to produce poly(N-vinyl carbazole)-polypyrrole/reduced graphene oxide (PNVC-PPy/RGO) nanocomposite. Fourier transform infrared spectroscopy (FTIR) confirmed the incorporation of RGO into the PNVC-PPy structure. The thermo-electric properties of PNVC-PPy increased with varying reduced graphene oxide (RGO) contents. Field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analyses showed the formation of PNVC-PPy/RGO nanocomposites with ordered structures. Raman spectroscopy analysis revealed the enhancement of conjugation length of the polymer nanocomposites suggesting enhanced electrical conductivity as measured by four-probe technique. Thermogravimetric analysis (TGA) exhibited significant changes in the thermal stability of the PNVC-PPy/RGO nanocomposites owing to the incorporation of RGO to PNVC-PPy copolymer. The strong π–π interactions between RGO and PNVC-PPy in PNVC-PPy/RGO nanocomposites were observed by the red shifting of the wavelengths in ultraviolet visible spectroscopy (UV–vis) when RGO was added into the polymer composites. The photoluminescence quenching induced by reduced graphene oxide in (PNVC-PPy/RGO) nanocomposite was attributed to the efficient electron transfer from PNVC-PPy copolymer to RGO.