Single‐Crystalline Dodecahedral and Octodecahedralα‐Fe₂O₃ Particles Synthesized by a Fluoride Anion–Assisted Hydrothermal Method

Novel Composites of α‐Fe2O3 Tetrakaidecahedron and Graphene Oxide as an Effective Photoelectrode with Enhanced Photocurrent Performances

“…The α-Fe 2 O 3 tetrakaidecahedrons prepared by a hydrothermal process without any organic additives display good crystallinity, which are modifi ed by graphene oxide afterward. Other than the previous reports involving viscous macromolecules, [ 25,27,28 ] F − anion, [ 26 ] and diethylenetriamine, [ 31 ] the hydrothermal synthesis of α-Fe 2 O 3 tetrakaidecahedrons is specially facile and environmental, which only uses FeCl 2 •4H 2 O, NaOH, and ultrapure H 2 O as reaction precursors. Through photoelectrochemical investigation, this kind of α-Fe 2 O 3 /graphene photoelectrode shows superior photocurrent response than that of pure α-Fe 2 O 3 with higher photocurrent and lower onset potential.…”

Synthetic Formation of Iron Oxides

“…The presence of various ligands in solution during oxide particle synthesis and in particular hematite has a significant effect on morphology: truncated [14] and full hexagonal bipyramid [15], rods [16], and tubes [17] can be obtained ( Figure 10.2). Indeed, the morphology of a crystal depends on the growth rates of the different crystallographic planes.…”

Tuning the Morphology of Metal Oxides for Catalytic Applications

“…174 Since the (110) plane has a higher density in Fe atom and its exposure would be catalytically more reactive than the (111) or (110) planes, 175 ␣-Fe 2 O 3 nanocubes with the lengths of 15-300 nm have been synthesized by aqueous-phase precipitation and hydrothermal processes with the aid of surfactants ( Figure 10.12b-d). [176][177][178][179] Polyhedral nanoparticles, such as rhombohedra, 180, 181 oblique parallelepiped, 182, 183 dodecahedra/ octahedral, 184 and tetrakaidecahedra, 185,186 are characterized with higher density of atomic steps, ledges, and kinks of high-index facets. Simple hydrolysis of FeCl 3 yielded ␣-Fe 2 O 3 rhombohedral crystals with the lateral size of 35-45 nm.…”

“…185 as the structure-directing agent ( Figure 10.13f-i). 184 Here, the concentration of F − that mediated the growing rates along the [001] and [100] orientations of Fe 2 O 3 nanocrystals was critically important in tailoring the shape of the final product. Higher F − concentration favored the formation of dodecahedral particles that preferentially exposed the (101) planes, but lower F − concentration yielded octadecahedral particles terminated by the (111) planes.…”