Multi-tiered distributions of arsenic in iron nanoparticles: Observation of dual redox functionality enabled by a core-shell structure.

Multi-tiered arsenic distributions within nanoscale zero-valent iron (nZVI) were observed upon reactions of nZVI with aqueous As(iii) species, suggesting arsenite oxidation and reduction may occur in parallel at different sub-domains of the nanoparticles owing to the particle's core-shell structure. New insights into arsenic remediation with iron nanomaterials are obtained.