Diffusion mechanisms of nanoparticles at metal interface in high- temperature molten salt thermal energy storage

L Cui and ZS Jing and PY Dong and XY Wang and MX Wu and XZ Du, APPLIED SURFACE SCIENCE, 713, 164293 (2025).

DOI: 10.1016/j.apsusc.2025.164293

Diffusion of nanoparticles into metal container wall of molten salt heat storage tank can effectively suppress molten salt-induced corrosion. In this study, diffusion processes between SiO2 nanoparticle and Fe, and between Al2O3 nanoparticle and Fe at high temperatures were compared. Results show a thicker SiO2/Fe interface than Al2O3/Fe, with thickness growing as temperature rises. New insights into diffusion were given from the perspectives of diffusion characteristics, migration paths and component characteristics of coordination compounds. It is found that SiO2 and Al2O3 diffuse as molecules, with SiO2/Fe following interstitial diffusion and Al2O3/Fe vacancy diffusion. The lower energy barrier of interstitial diffusion makes it easier to occur, leading to the better performance of SiO2 nanoparticle. Additionally, new coordination compounds formed at the interface, with SiO2/Fe producing more compounds than Al2O3/Fe. Different from the multiple Si-Fe and Si-Al compounds, Fe-O is found to be a certain metal coordination compound. These findings advance the understanding of diffusion mechanisms of nanoparticles at metal interface.

Return to Publications page