A simple strategy to improve the yield of graphene nanosheets in the anodic exfoliation of graphite foil

Strategies that improve the yield of graphene nanosheets in anodic exfoliation processes are desirable for the mass production of this material. Here, a simple pre-treatment of graphite foil with concentrated H2SO4 is demonstrated to be such an effective strategy, affording overall exfoliation yields up to ∼50 wt% under certain experimental conditions, compared with a baseline value of ∼10 wt% for untreated graphite. Filling of inner voids and interstices of the graphite foil with H2SO4 molecules was concluded to be responsible for the enhanced exfoliation performance. Additional approaches to further increase the anodic exfoliation yield are also proposed and discussed.