| Abstract [eng] |
The master’s thesis project addresses capacitive and photoelectrochemical properties of zinc cobalt oxide (ZCO) coatings. For the synthesis of ZnCo2O4, a simple combustion method was chosen due to its fast process and good product quality. The resulting solution is initially annealed at 300 ℃ and the resulting ZCO powder is annealed at 600 ℃. Methods used to determine the morphology, topography and composition of the product: scanning electron microscopy (SEM), energy-dispersive X-ray spectrography (EDS), X-ray diffraction analysis (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The analyses compare annealed and unannealed ZCO spinel, the latter consisting of a mixture of ZnO and Co3O4, carbon structures, carboxyl groups and other impurities. In the annealed compound, pure ZnCo2O4 spinel was obtained. The coatings are deposited on TEC-15 glass wafers using the spray method and varying the number of layers from 1 to 20. The electrochemical properties of the synthesized coatings were investigated by linear sweep voltammetry (LSV). Based on the results obtained, the photoelectrochemical efficiency (IPCE) and the photoconversion efficiency (ABPE) are calculated. The capacitive properties of the thin-film coatings are investigated using the charge/discharge method and the specific power, specific energy and specific capacitance are calculated. It was found that the best capacitive (SP = 21250 W∙h/kg; SE = 42.52 W/kg; SC = 423.73 F/g) and photoelectrochemical (IPCE = 11.44 %; ABPE = 2.36 %) performance was obtained for the 16-layer (ZnCo2O4) coating, with a discharge time of 7,2 seconds. |
