Novel multilamellar mesostructured molybdenum oxide nanofibers and nanobelts: synthesis and characterization

One-dimensional molybdenum oxide nanostructures with layered mesostructures were prepared directly from commercial bulk MoO3 crystals by a surfactant-templated hydrothermal process. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, infrared spectra, and thermal analyses have been used to characterize the obtained molybdenum oxide nanomaterials. By use of cetyltrimethylammonium bromide as the structure-directing template, novel molybdenum oxide nanofibers with triple interlayer distances of 2.84, 2.66, and 2.46 nm have been obtained. The nanofibers have diameters of 20-100 nm and length up to 20 microm. The growth of multilamellar molybdenum oxide nanofibers can be interpreted by the combination of surfactant/inorganic self-assembly process and host/guest intercalation chemistry. On the basis of the X-ray diffraction and infrared results, a possible arrangement of surfactant in the interlayer space of molybdenum oxide by bilayer micelles with different tilt angles has been proposed. In addition, the thermal stability of surfactant has been improved by intercalation. Moreover, molybdenum oxide nanobelts with two kinds of interlayered structures were also produced in the presence of n-alkylamines (n = 12, 14, 16, and 18) following a similar method, these nanobelts show length up to more than 10 microm, width ranging between 200 and 600 microm, and width-to-thickness ratios of about 3-12. A linear relationship is observed between the interlayer distance and the number of carbon atoms in n-alkyl chains.