凯发

Hexagonal boronnitride (h-BN), a two-dimensional (2D) layered material, can be stable at 1500oCin air and will not react with most of chemicals. Several applications havebeen proposed for this material including its use as a smooth substrate forgraphene devices, as barrier layers for vertical hybrid atomic layer stackswith a few graphene and h-BN layers. In this talk, we first demonstrate synthesisof large-scale ultrathin coatings of high quality h-BN layers with controlledthicknesses from double layers to bulk. We show that such ultrathin h-BN filmsare impervious to oxygen diffusion even at high temperatures and can serve ashigh-performance oxidation resistant coatings for nickel up to 1100oCin oxidizing atmospheres. Next, large area continuous h-BN film grown on nickel foil by CVD method wasthen transferred onto sputtered copper as a corrosion passivation coating. Thecorrosion passivation performance in Na2SO4 solution ofbare and coated copper was investigated by electrochemical methods includingcyclic voltammetry (CV), Tafel polarization and electrochemical impedancespectroscopy (EIS). CV and Tafel analysis indicate that h-BN coating couldeffectively suppress the anodic dissolution of copper. EIS fitting resultsuggests that defects are the dominant leakage source on h-BN film and improvedanti-corrosion performances could be achieved by further passivating thosedefects.