Understanding Oxygen Bubble‐Triggered Exfoliation of Graphite Toward the Low‐Defect Graphene

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 H 2 SO 4 and H 2 O 2 plays an important role in the procession of exfoliation of graphite. Moreover, density functional theory (DFT) simulations exhibit that H 2 O 2 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 H 2 O 2 , 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 °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.