MoO(3) nanostructures with different morphologies, such as helical nanosheets, crosslike nanoflowers, and nanobelts, have been synthesized on a large scale by an environmentally friendly chemical route. The evolution process from helical nanosheets to crosslike nanoflowers to nanobelts is observed for the first time. The influences of reaction time and the molar ratio of molybdenum and H(2)O(2) on the morphologies of MoO(3) nanostructures have been investigated. The synthetic process is environmentally friendly and may be extended to synthesize nanostructures of other metal (W, Ti, and Cr) oxides.

One-dimensional polyaniline nanostructures with controllable surfaces and diameters have been synthesized using vanadic acid as the oxidant in the absence of porous templates and structural directing molecules. The synthetic parameters, such as the concentrations of HCl, and types of oxdiants on the morphologies, diameters, and molecular structures of one-dimensional polyaniline nanostructures have been investigated. As the concentration of HCl is low, polyaniline nanorods with diameters of 10-20 nm and length up to 50-60 nm can be aligned radially along the length axis on the surfaces of polyaniline nanofibers. With the concentration of HCl increased, the diameters of one-dimensional polyaniline nanostructures decrease from 150-300 to 40-100 nm, and the surfaces of one-dimensional polyaniline nanostructures become smooth. The possible formation mechanism of one-dimensional polyaniline nanostructures using vanadic acid as the oxidant has been discussed.

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Low-valent vanadium oxide nanostructures have been synthesized in large quantities using commercial V2O5 powder as the precursor by a facile reduction method. The crystal structures and morphologies of vanadium oxide nanostructures can be adjusted by altering the concentrations and types of reductants. VO2(B) nanostructures are fabricated using oxalic acid as the reductant. VO2(B) nanobelts with widths of 80-150 nm, thicknesses of 20-30 nm, and lengths up to several micrometers can evolve to olive-like nanostructures composed of nanosheets with thicknesses of several nanometers and lateral dimensions of several micrometers as the concentration of oxalic acid increases. H2V3O8 nanobelts with widths of 200-300 nm, thicknesses of 10-20 nm, and lengths up to several 10s of micrometers are obtained under the reduction of V2O5 powder with ethanol. The belt-shaped morphologies of H2V3O8 are not affected by the concentration of ethanol.