Corrosion Resistant, Graphene-Like Carbon Coated Iron Oxide Nanocrystals Formed During Liquid Phase Synthesis

C. Masterson, A. Garcia-Mendoza, A. Prakash, V.L. Colvin
Brown University,
United States

Keywords: nanoparticles, graphene, corrosion resistant


Here we report a solution-phase strategy for depositing ultrathin, graphene-like carbon onto iron oxide nanocrystals (NCs). The thermal decomposition of iron carboxylates is a well-known method for generating uniform, size tunable iron oxide NCs. When this reaction is completed at elevated temperatures, and for longer times, the nanomaterials become unreactive to further growth.X-ray photoelectron and Raman spec-troscopy reveal that these materials contain graphene-like carbon with clear signatures of sp2 carbon. Metal carboxylates can decompose and yield carbon monoxide which we detect via GC-MS. We speculate that when this CO is generated near a growing iron oxide surface, it disproportionates to yield carbon dioxide and elemental carbon as ultrathin graphene. The coated magnetic nanomaterials survive treatment with concentrated nitric acid, retaining their magnetic properties even under very aggressive chemical conditions. Our approach is notable given that a low temperature, solution-phase route for forming carbon materials such as graphene from the bottom-up has remained elusive.