Corrosion behaviors and kinetics of nanoscale zero-valent iron in water: A review

Knowledge on corrosion behaviors and kinetics of nanoscale zero-valent iron (nZVI) in aquatic environment is particularly significant for understanding the reactivity, longevity and stability of nZVI, as well as providing theoretical guidance for developing a cost-effective nZVI-based technology and designing large-scale applications. Herein, this review gives a holistic overview on the corrosion behaviors and kinetics of nZVI in water. Firstly, Eh-pH diagram is introduced to predict the thermodynamics trend of iron corrosion. The morphological, structural, and compositional evolution of (modified-) nZVI under different environmental conditions, assisted with microscopic and spectroscopic evidence, is then summarized. Afterwards, common analytical methods and characterization technologies are categorized to establish time-resolved corrosion kinetics of nZVI in water. Specifically, stable models for calculating the corrosion rate constant of nZVI as well as electrochemical methods for monitoring the redox reaction are discussed, emphasizing their capabilities in studying the dynamic iron corrosion processes. Finally, in the future, more efforts are encouraged to study the corrosion behaviors of nZVI in long-term practical application and further build nanoparticles with precisely tailored properties. We expect that our work can deepen the understanding of the nZVI chemistry in aquatic environment.