Mapping the reactions of hexavalent chromium [Cr(vi)] in iron nanoparticles using spherical aberration corrected scanning transmission electron microscopy (Cs-STEM)

Abstract

Near atomic-resolution elemental mapping of the reactions of Cr(VI) with nanoscale zero-valent iron (nZVI) is achieved by Cs-STEM integrated with EDS. Results capture for the first time detailed images that Cr diffuses across the oxide layer and accumulates primarily in the core area of nZVI, provide direct evidence of the intraparticle diffusion and reaction mechanism of Cr(VI) in a single nZVI particle, and demonstrate a unique approach for encapsulation of toxic substances.