Superanticorrosive Graphene Nanosheets through π Deposition of Boron Nitride Nanodots

Graphene has been demonstrated as an excellent protection material because of its complete impermeability. Unfortunately, graphene fails to prevent metals corrosion for the long term because its essential conductivity promotes the electrochemical reaction between the graphene and the metals. In this work we encapsulated commercial graphene nanosheets (GNSs) with boron nitride nanodots (BNNDs). Interestingly, introduction of BNNDs also allowed the fabrication of aqueous compatible BNND@ GNSs complex dispersions with an expected high concentration of 5 mg/mL and stability over 1 month under environmental conditions. The long-term anticorrosion performance of BNND@GNSs-reinforced epoxy coatings (BNND@GNSs/EP) are comparably evaluated by aging in 3.5% NaCl(aq). Our work reveals that the BNNDs BNND@GNSs act as a spacer separating GNSs and metals to prevent BNND@GNSs from connecting with the metals, which suppresses the galvanic corrosion and achieves superanticorrosion. Electrochemical results revealed that the corrosion rate and coating impedance of steel coated by the composite coating with 0.1 wt % of BNND@GNSs decreased 280-fold and increased by 2 orders, respectively, than that of steel under the neat epoxy system. With the properties of GNSs not compromised by BNNDs, this method would largely facilitate its practical applications on polymer anticorrosion fields.