3D TEM study on hollow α-Fe2O3 nanostructures and nanorings

Publication date: Available online 10 December 2019Source: Progress in Natural Science: Materials InternationalAuthor(s): Ming Lin, Enyi Ye, Jia ZhangAbstractControlled synthesis of hollow structures with non-spherical holes is significant in fabricating nanomaterials with well-defined geometries and specific catalytic and electrochemical properties. Here we report the synthesis of uniform hexagonal bipyramid hematite (α-Fe2O3) nanoparticles with hollow and faceted interior via directional etching process in solution. The delicate hollow structures were investigated by electron tomography and growth mechanism was revealed unambiguously. The three-dimensional visualization demonstrates the outside surfaces of hematite particles are enclosed by six {104} and twelve {113} planes, due to the stabilizing effect of the F− anions on the exposed surfaces. The concurrent etching process is a reverse process of crystal growth and leads to the dissolution occurring at the edges and tips of the hexagonal bipyramid particles, resulting in the perforated crystals with exposed {102} internal facets or overetched nanorings with hexagonal cross-sections. This nanoscale growth and etching process still strictly follows the bulk crystal growth mechanism, thus shedding light on the synthesis of other nanoparticle with controlled morphologies and porous structures.Graphical abstract
Source: Progress in Natural Science: Materials International - Category: Materials Science Source Type: research