Scalable production of few layered graphene by soft ball-microsphere rolling transfer

Graphene is one of the most fantastic nanomaterials and has attracted much attention in various fields. The industrial applications are hindered since there is no effective path to produce scalable few layered graphene without functional groups. Here we report a simple effective green path, a soft ball-microsphere rolling transfer process, to produce bulk quantity of few layered graphene without functionalization. The as-produced graphene nanosheets have been demonstrated by height statistics to have 1-10 layers with average layers of 3.8 +/- 1.9 and further confirmed by spectroscopic metrics. No functional groups or contamination have been introduced in the processes. No extra time-consuming purification processes are needed. About 70 mg graphene sheets were obtained from one 500 ml agate tank after process carried out at a speed of 100 rpm for 2 h. The exfoliation can be easily extended to industrial scale by using larger and more agate tanks without the sacrifice of yields. (C) 2019 Elsevier Ltd. All rights reserved.