▎ 摘　　要

Although graphene has been developed and widely used in many fields over the past decades, the effect of oxygen (O-2) on the exfoliation of graphite is still unclear. Here, a simple bubble-triggered exfoliation method is employed for controllable synthesis of graphene nanoplatelets (GNPs) with low-oxidation level and high electrical conductivity. The exfoliation process is studied and a formation mechanism for the synthesis of the low-defect GNPs is proposed. The results show that the synergistic effect of H2SO4 and H2O2 plays an important role in the procession of exfoliation of graphite. Moreover, density functional theory (DFT) simulations exhibit that H2O2 would preferentially adsorb on the edge of graphite, indicating the possibility to initiate the exfoliation by O-2. In the whole process, some oxygen free radicals can be released from H2O2, resulting in some O-2 and oxygen functional groups formed on the graphite edge, and which can finally lead to the fast exfoliation of graphite. In addition, a time-dependent temperature profile under an applied voltage of 5 V exhibits a steady-state with temperature up to 275 degrees C. Overall, this work elucidates the selectivity of gas bubble absorbed on the side edge of graphite and presents a potential application for high-electrical conductivity graphene.