Influence of multi-walled carbon nanotubes on electrochemical performance of transparent graphene electrodes

In this work, carbon–carbon nanocomposites as transparent electrodes were prepared by a chemical reduction of graphite oxide (GO) and multi-walled carbon nanotubes (MWNTs). The electric, optical, and electrochemical properties of graphene-MWNT nanocomposites (G-MCs) were investigated as a function of the MWNT content. It was found that chemically bonded G-MCs were successfully formed with a reduction of the functional groups of the GO and acid-treated MWNTs, resulting in the conjugation of 1D MWNTs onto a 2D graphene surface. The electrical conductivity of the graphene was significantly enhanced by introducing the MWNTs. In addition, the G-MCs showed improved current density and high efficiency compared with graphene alone. This indicated that the improved electrochemical performance of the G-MCs can be attributed to the increase in the activity and electrical conductivity enhanced by π–π interaction between graphene and MWNTs.

The surface resistance of graphene decreased with the incorporation of MWNTs due to the bridge effect of MWNTs incorporated between graphene.Figure optionsDownload as PowerPoint slideHighlights
► We fabricated the MWNT-coated graphene nanocomposites (G-MC).
► G-MC showed enhanced electrical conductivity compared to graphene and MWNT alone.
► The current density of G-MC was higher than that of graphene and MWNT alone.
► The enhanced properties of G-MC are due to bridge effect of MWNTs between graphene.