Recently, nanostructured materials have attracted great interest in the field of lithium-ion batteries, essentially because of their substantial advantages, such as short transport path lengths for both electrons and Li + ions, a large amount of contact surface area between the electrode and electrolyte, and large flexibility and toughness for accommodating strain introduced by Li + insertion/extraction. [1][2][3] Among the transition-metal oxides, nanostructured MoO 3 has been extensively investigated as a key material for fundamental research and technological applications in optical devices, smart windows, catalysts, sensors, lubricants, and electrochemical storage. [4][5][6][7] There are two basic polytypes of One might take advantage of the intrinsic structural anisotropy of a-MoO 3 for tuning its properties by interlayer structural modification, annealing, and lithiation. [5,8,9] In this Communication, we report the electroactivity of a-MoO 3 nanobelts after lithiation that show superior performance to nonlithiated a-MoO 3 nanobelts. An X-ray diffraction (XRD) measurement was performed using a D/MAX-III X-ray diffractometer. Fourier-transformed infrared (FTIR) absorption spectra were recorded using the 60-SXB IR spectrometer. Raman spectra were taken using a Renishaw RM-1000 laser Raman microscopy system. Scanning electron microscopy (SEM) images were collected with a JSM-5610 and FES-EM LEO 1530. Transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected-area electron diffraction (SAED) were recorded by using a JEOL JEM-2010 FEF microscope. The electrochemical properties were studied with a multichannel battery testing system. Batteries were fabricated using a lithium pellet as the negative electrode; 1 M solution of LiPF 6 in ethylene carbon (EC)/dimethyl carbonate (DMC) as the electrolyte; and a pellet made of the nanobelts, acetylene black and PTFE in a 10:7:1 ratio as the positive electrode. The fabrication of a single nanobelt-based device has been described in detail elsewhere. [10] XRD measurement was first used to study the phase and lattice modification of the nanobelts before and after lithiation (Fig. 1A). The diffraction peaks of the XRD pattern for both samples can be readily indexed to be orthorhombic with lattice constants of a = 3.962 Å, b = 13.85 Å, c = 3.697 Å (International Centre for Diffraction Data (ICDD) No. . No peaks of any other phases were detected, indicating the high purity of the MoO 3 nanobelts. For the non-lithiated MoO 3 nanobelts, the stronger intensities of (020), (040), and (060) peaks than those for the bulk MoO 3 (Fig. S1, Supporting Information) indicates the anisotropic growth of the nanostructure as well as the preferred orientation of the nanobelts on the substrate. Importantly, in comparison to the nonlithiated sample, there is a small shift of the (020) peak toward a lower diffraction angle for the lithiated sample. This is direct evidence of an expanded b-plane interlayer distance for 0.065 Å after lithiation, ...

No abstract

No abstract

In this work, a facile route using a simple solvothermal reaction and sequential calcinations to synthesize porous R-Fe 2 O 3 flower-like nanostructures without employing templates or matrices for self-assembly is presented. The flower-like nanostructures are composed of nanosheets with a thickness of about 20 nm, which are characterized by field-emission scanning electron microscopy (FESEM). Influencing factors such as the dosage of reactants and the solvents are systematically investigated. A possible formation mechanism for the flower-like nanostructure is proposed. A BET test shows that the product is porous and has a large surface area. The electrochemical, magnetic, and photocatalytic properties of the as-obtained R-Fe 2 O 3 3D nanostructure are systematically investigated. The result shows that these properties are greatly affected by the porous structure.