A mechanical surface treatment is presented by using adhesive tape to modify the surface morphology of graphene cathodes and to improve their field emission properties. The treated graphene cathodes have numerous vertical sharp edges, which act as excellent field emission sites. Effectively improved field emission properties with low turn on field, low threshold field, high emission current density and high field enhancement factor are obtained due to the full utilization of the unique structure and excellent properties of graphene. (C) 2013 Elsevier B. V. All rights reserved.