Role of reduced graphene oxide in dielectric enhancement of ferroelectric polymers composites

•High dielectric constant and low dielectric loss are achieved when introducing a small amount of rGO into CCTO composites.•Enhanced dielectric properties originate from both induced polarization effect and intrinsic high dielectric constant of rGO.•Tunneling effect between rGO plays an important role in electrical conductivity and dielectric loss of the composites.