Microscopic and spectroscopic investigation of carbon nanotubes-rhenium nanocomposites fabricated in different conditions

The article describes the morphology of carbon-metal nanocomposites consisting of nanostructured rhenium permanently attached to carbon nanomaterials, in the form of single-walled (SWCNTs), double-walled (DWCNTs) or multi-walled carbon nanotubes (MWCNTs). Such nanocomposites are produced as a result of the high-temperature reduction of a rhenium precursor, including HReO4 or NH4ReO4, to metallic rhenium, deposited on the previously functionalised carbon nanomaterials in the form of nanoparticles whose size and dispersion are dependent upon the conditions of a technological process. Microscopic examinations carried out with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed a differentiated structure of the presented nanocomposites depending on impregnation time in a rhenium precursor, which is one of the manufacturing steps of such materials. It has been demonstrated that longer impregnation time brings favourable results for material homogeneity in the whole volume. Moreover, the Raman spectroscopy results of functionalised carbon nanotubes and carbon nanotubes decorated with rhenium also has been presented.