| Abstract [eng] |
Nowadays, supercapacitors have a worldwide interest due to their high-power density and length of service. For this reason transition metal sulfides are being studied as a substance for energy storage because they can exist in several structures and demonstrates exceptional electrical conductivity [1]. The perfect example could be cobalt sulfides that have the above properties and might be used in lithium-ion or rechargeable alkaline batteries (as anodes), magnetic materials and catalysts. Nevertheless, despite these excellent possessions, scientists still face difficulties in synthesizing pure material. However, it is known, that conditions like temperature, reactant concentration and reaction time has the largest impact on the formation of certain structures that determine the properties and application of the resulting material [2]. The aim of this work is to form semiconductors cobalt sulfide layers on the surface of polyamide 6 and to investigate the properties of the obtained thin films using various analysis. Polyamide 6 films used in this research were obtained from Ensinger (Germany). Before the experiment, PA films were boiled in distilled water for 2 h. After that, PA 6 films were kept in pentathionic acid (H2S5O6) from 1.0 to 5.0 h at room temperature. After interaction with acid, samples were treated with the 0.16 mol⋅dm–3 solution of cobalt sulphate, (CoSO4 ⋅ 7H2O) for 10 minutes at different temperatures – 60, 70 and 80 ºC (5 samples for each temperature). After the formation of cobalt sulfide layers on PA 6 surfaces, films were investigated using X-ray diffraction (XRD) and atomic force microscopy (AFM) analysis. Morphological studies showed that sample demonstrates the best properties when sulfurized for 1 hour and kept in a cobalt salt solution at 60 oC - it has the most homogeneous surface possibly due to the evenly formed layer of CoxSy (Fig. 1 (a)). Meanwhile, when sample was sulfurized for 5 hours and kept at 80 oC temperature cobalt salt solution, the roughest surface was obtained because it failed to form the layer of cobalt sulfides (Fig. 1 (b)). |
