Size-controlled synthesis of Rod-like α-FeOOH nanostructure

One-dimensional goethite (α-FeOOH) nanorods were successfully fabricated by a hydrothermal route without any template. Experimental results reveal that concentrations of Fe3 + and ethylenediaminetetraacetic disodium salt (Na2EDTA) affect the phase composition and size of the as-synthesized products. The size of the rod-like α-FeOOH increased when the concentration of Na2EDTA was increased, where Na2EDTA acts as a nucleation inhibitor. α-Fe2O3 nanoparticles were produced when the concentration of Fe3 + was increased from 0.02 to 0.08 and 0.40 M. A possible formation mechanism was proposed based on the results of the time dependent experiments. Different electrolytes and surfactants can affect the size and the aspect ratio of the as-prepared nanorod-like α-FeOOH. Na2SO4 induced the decreasing of the size of the as-prepared sample. KCl and PVP affected the aspect ratio of the nanorods.

Graphical abstractThe α-FeOOH crystal nuclei were formed by the reaction of Fe3 + with OH−. These nanocrystals further aggregated into rod-like nanocrystals by dehydration. As the reaction time was increased further, well-defined α­FeOOH rod-like structures were finally formed.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The size of the nanorod of the α-FeOOH was changed by using Na2EDTA. ► Substituting the α-FeOOH, α-Fe2O3 was produced by increasing the concentration of Fe3 +. ► Aggregating processes were proposed to elucidate the growth of nanorods of α-FeOOH.