Synthesis of Rhombic Dodecahedral Fe₃O₄ Nanocrystals with Exposed High-Energy {110} Facets and Their Peroxidase-like Activity and Lithium Storage Properties

Abstract

Large quantities of monodispersed single-crystal rhombic dodecahedral (RD) Fe 3 O 4 nanocrystals (NCs) bounded by high-energy {110} facets were prepared by using a one-pot toluene−water two-phase interfacial reaction method. By adjusting the Fe(acac) 3 concentration and the volume of hydrazine hydrate, their sizes could be controlled in the range from 60 to 100 nm. The formation of these RD Fe 3 O 4 NCs with exposed highenergy {110} surfaces might be the result of selective stabilization of such unstable facets by the C 17 H 33 COO − based on FT-IR analysis. The magnetic measurement revealed that the saturation magnetization (M s ) of the RD Fe 3 O 4 NCs was 85 emu/g at room temperature. When used as peroxidase mimetics, the prepared RD Fe 3 O 4 NCs showed excellent peroxidase-like catalytic activity toward oxidation of the substrate 3,3′,5,5′-tetramethylbenzidine and degradation of the aniline compound methylene blue dye in the presence of H 2 O 2 . When tested as anode materials for lithium-ion batteries, these as-obtained RD Fe 3 O 4 NCs showed a high initial discharge capacity of 1147 mA h g −1 at the current density of 0.2 C, a good cycle performance (362 mA h g −1 at 0.2 C after 100 cycles and 191 mA h g −1 at 1 C up to 130 cycles), and good rate capability at high current rates of 1−4 C.

Facile synthesis, shape evolution and magnetic properties of polyhedral 50-facet Fe3O4nanocrystals partially enclosed by {311} high-index planes

“…50 The individual Fe 3 O 4 nanoparticles were unstable due to a high surface energy, and thus they tended to aggregate rapidly to form spherical nanospheres. 39,40 However, the surface energies of the different crystal facets can be altered by selective adsorption of the different species such as surfactants, polymers, or inorganic ions in solution. 4b.…”

“…22,23 In the past decade, a range of techniques have been developed for the controllable synthesis of magnetic nanomaterials, and various Fe 3 O 4 nanostructures have been prepared, including nanoparticles, nanospheres, nanocubes, octahedra, nanorods, nanowires, nanosheets, etc. Until now, Fe 3 O 4 octahedrons surrounded by eight {111} facets, 28 36,37 and magnetite rhombic dodecahedral particles exposing the active {110} basal surfaces [38][39][40] have been fabricated. Until now, Fe 3 O 4 octahedrons surrounded by eight {111} facets, 28 36,37 and magnetite rhombic dodecahedral particles exposing the active {110} basal surfaces [38][39][40] have been fabricated.…”

Adsorption of biomedical coating molecules, amino acids, and short peptides on magnetite (110)

“…A pure (100) morphology is cubic, while (110) and (111) morphologies are rhombododecahedral and octahedral, respectively. Natural and synthetic magnetite most commonly crystallizes in the octahedral (111) morphology, but the (110) and mixed (110)/(111) rhombododecahedral morphologies have also been observed/synthesized, 8,10 which motivates us to focus on the (110) surface in the present study. In comparison to the (100) and (111) surfaces, which have received significant attention in recent years, 11,12 the Fe 3 O 4 (110) surface has been studied much less extensively.…”

Shape-Evolution and Growth Mechanism of Fe3O4Polyhedrons

“…Magnetite (Fe 3 O 4 ), a traditional material, has found many applications, such as magnetic fluids [5,6] and microwave absorption [7,8]. Recently, Fe 3 O 4 microand nanoparticles with specific facets have attracted growing interest because of their unique performance in magnetic resonance imaging (MRI) [9,10] and drug delivery [9,11] and their catalytic and lithium storage properties [12][13][14][15]. Therefore, it remains necessary to explore more effective shape-control methods for Fe 3 O 4 crystals.…”