Interfacial diffusion behaviors of ZnO nanoparticles in metal Fe for high-temperature systems: a molecular dynamics study
摘要
As renewable energies become viable energy sources, efficient thermal energy storage still faces challenges associated with the corrosion of metal containers in high-temperature molten salt systems. Although adding ZnO nanoparticles can mitigate the corrosiveness of molten salts in recent experimental studies, the underlying nanoparticle–metal interfacial mechanism has been rarely explored. In this work, molecular dynamics (MD) simulations were used to investigate the high-temperature interfacial diffusion behavior between the Fe and ZnO atoms. The results demonstrate that temperature significantly influences diffusion at the ZnO–Fe interface. At 823 K, the self-diffusion coefficient of Fe is observed to be 1.09 × 10−6 Å2 ps−1, while it is 6.99 × 10−7 Å2 ps−1 for ZnO. At 1423 K, these coefficients increase to 5.91 × 10−5 Å2 ps−1 for Fe and 1.88 × 10−5 Å2 ps−1 for ZnO. Energy and microstructural analyses further show the enhanced atomic activity and local structural rearrangement in interfacial regions at higher temperatures. This study sheds light on the understanding of nanoparticle-Fe interfacial behaviors by providing atomic-scale insight into the high-temperature interaction between the ZnO and Fe surfaces under thermal storage conditions.