Impermeability of boron nitride defect-sensitive monolayer with atomic-oxygen-healing ability

Hexagonal boron nitride (h-BN) is a new type of anti-corrosion coating. However, a large number of studies have shown that defects can significantly reduce the barrier property of h-BN. So how to repair the defect of h-BN is a problem to be solved. In this study, we used the density functional theory of the first principle to calculate the barrier properties of perfect h-BN and the h-BN with various vacancies. The study showed that monolayer h-BN has impermeability to all gas molecules, and vacancies can greatly reduce the barrier ability of h-BN to oxygen molecules. Fortunately, atomic oxygen can block the vacancy site of h-BN by chemical adsorption, thereby reducing the impact of vacancies on h-BN. Compared to the situation before the vacancy repaired, the barrier ability of h-BN to oxygen molecules was greatly increased after being repaired. In addition, the electron cloud density at vacancies after the repair (with) atomic oxygen was also greatly increased. Therefore, atomic oxygen can repair vacancies of h-BN and enhance the barrier ability of the defective h-BN. The research in this paper is of some significance. It is helpful to repair h-BN and evaluate corrosion resistance of h-BN in oxygen-rich or atomic-oxygen-rich environment.