Preparation and evaluation of nanocomposites based on transitional oxides and carbon materials for electrochemical applications.

In the present paper, it was studied the possibility of obtaining nickel oxide (NiO) for developing nanocomposites based on transitional oxides and carbon materials for electrochemical applications. In order to obtain nanostructured NiO, the precipitation method was chosen and the influence of surfactants (e.g. SDS, CTAB, PEG, IGEPAL CA-630 and hydroxypropyl cellulose) on the structural and morphological properties of NiO was established. The oxide precursor was treated at a maximum of 700 °C. The used carbon material is reduced graphene oxide (RGO) and was obtained by the Hummer's method. The ex-situ method was used for obtaining nanocomposites, consisting of the formation of a homogeneous mixture between the fillers (RGO and NiO) and the polymeric matrix polyvinylidene fluoride (PVDF). The influence of filler concentration on the electroactive β-phase of PVDF was evaluated. The developed materials were analyzed from a morphological and structural point of view and the wetting capacity was determined, using characterization techniques, such as FTIR and EDX spectroscopy, X-ray diffraction, SEM microscopy and goniometry. The morphological study shows the synthesis of oxide particles with dimensions below 80 nm, their insertion in the graphene domains and close interaction between composite components took place. Structural studies indicate crystalline purity of the oxide and increased electroactive β phase nucleation by the incorporation of RGO and NiO into the PVDF matrix. The PVDF-RGO-NiO composite has a hydrophilic character. The ability of PVDF-RGO-NiO nanocomposites to store charge was evaluated via cyclic voltammetry. [ABSTRACT FROM AUTHOR]