Carbon nanosheets by microwave plasma enhanced chemical vapor deposition in CH4-Ar system

► Catalyst-free CNSs were firstly achieved in Ar-CH4 by MPECVD at 450-500 °C. ► The CNSs possess many shape edges which consist of a few layers of graphene. ► The CNSs have demonstrated a faster electron transfer. ► The results provide the possibility for lower-temperature growth of graphene.