A new route for preparing multi-oxide nanocomposites of nanoparticles-decorated nanotubes

The development of synthetic methods to prepare novel metal oxide nanocomposites is a field of materials chemistry with many technological implications. First, new properties can emerge due to the synergistic interactions between distinct metal-oxide phases combined in one single nanocomposite. Second, particular morphologies can be obtained by adjusting the nanocomposites' architecture to fulfill the needs of specific technological applications. Here, to address the need for new synthetic methods, we present a direct route for preparing multi-oxide inorganic nanocomposites with the specific architecture of nanoparticles decorating nanotubes. We impregnated hematite nanotubes with a metallo-organic precursor of nickel and, subsequently, we thermally decomposed it, in sequential impregnation-decomposition cycles (IDC). Materials were characterized (XRD, SEM, TEM, EELS) and the nanocomposite obtained is composed of NiO nanospheres grown on the walls of hematite nanotubes (Figure 1). Hematite nanotubes were morphologically and chemically stable during the synthetic process, thus having a potential use for different applications that require Fe2O3 stability. Virtually any individual metallo-organic precursor/combinations of precursors can be used in the synthetic route presented here. Therefore, it could be explored to obtain tailored nanocomposites consisting of controlled-size nanoparticles with different oxides combinations decorating the walls of nanotubes, with potential use in catalysis and biomedicine.