Facile Template-Free Synthesis and Characterization of Elliptic α-Fe₂O₃ Superstructures

Abstract

In this work, elliptic single-crystalline α-Fe2O3 superstructures are prepared successfully by a facile hydrothermal method independent of surfactants or templates. The as-obtained products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The elliptic superstructures are composed of nanorods with a mean diameter of ca. 40 nm and an average length of ca. 200 nm. By properly monitoring the component of the reaction system, the morphology of the α-Fe2O3 superstructures can also be tuned to be spherical (consist of nanosheets) and quasi spindle-like (consist of integrated irregular blocks). On the basis of a series of contrast experiments over time, the probable growth mechanism and fabrication process of the products were proposed. The magnetic and electrochemical properties of the as obtained α-Fe2O3 superstructures with different morphologies are investigated systematically. The results show that these properties are greatly influenced by the special structures of the products. This work provides an additional strategy to prepared self-assembled superstructures with tailored morphologies (both for the building units and the overall products) and properties.

Metal oxide mesocrystals with tailored structures and properties for energy conversion and storage applications

“…This definition has been developed in recent years, where MCs are defined entirely according to their structures rather than their formation mechanism. 12 In this decade, a variety of MCs of metal oxides (for example, TiO 2 , [13][14][15][16][17][18][19][20][21][22][23] ZnO, [24][25][26][27][28][29][30][31][32][33][34] hematite (a-Fe 2 O 3 ), [35][36][37][38][39][40] maghemite (g-Fe 2 O 3 ), 41 Co 3 O 4 , 42 SnO, [43][44][45] Ag 2 O, 46 CuO [47][48][49] ), metal chalcogenides (for example, ZnS, 50,51 PbS, 52 PbSe 53,54 ), metals (for example, Au, 55 Ag, 56,57 Cu, 58 Pt, 59,60 Pd 61 ), organic compounds (for example, DL-alanine, 62,63…”

Sb2S3 with Various Nanostructures: Controllable Synthesis, Formation Mechanism, and Electrochemical Performance toward Lithium Storage

“…The sheaf-like Sb 2 S 3 superstructures are superior to the other samples, with the highest lithium storage capacity, lowest irreversible loss, and excellent cycling performance, which may be attributed to its special structure and smaller size of nanorods. [47] The sheaf-like Sb 2 S 3 superstructures are composed of nanorods with a relatively smaller diameter; this special structure favors both the diffusion of the lithium ion and the electrolyte and Sb 2 S 3 . Therefore, better electrochemical property is observed for the sheaflike Sb 2 S 3 superstructures.…”

Dramatic enhancement of catalytic activity over transition metal substituted hematite

“…Fabrication of a-Fe 2 O 3 was carried out in a modified method [38]. In a typical experiment, 0.972 g of FeCl 3 Á6H 2 O was added to 60 mL of deionized water and allowed to stir for 30 min.…”