Synthesis and characterization of RuO2 thick film supercapacitor electrode: the effect of low temperature

This study involves the preparation of ruthenium oxide (RuO2) thick films by a different method than those reported in the literature and the investigation of their dielectric properties. The substrates were coated with RuO2 thick films deposited using a mixture of invertase enzyme and ruthenium ions dissolved in water. Scanning electron microscopy-energy dispersive X-ray spectroscopy was employed for surface analysis of the films. Current/potential measurements were used to examine dielectric properties and X-ray diffraction to examine structural properties. The capacitance per unit mass of RuO2 thick films produced with invertase enzyme in amorphous structure was found to be 845 F g(-1). Regarding energy dispersive X-ray spectroscopy analysis, thick films were found to contain around 79.15% ruthenium, evenly distributed on the surface of the films. In addition, we performed capacitance measurements for different temperatures and got very interesting results

UV region supercapacitor: Bi-doped natural MgO rock salt thin film

This study is based on MgO thin films, on which different amounts of bismuth were doped. XRD, SEM and EDX were performed for the characterization of thin films, whereas capacitance of the films was examined through current-voltage measurements. In addition, capacitance of these films was measured in the environments with violet, green, red and yellow lighting. It was found that under violet light, in other words around the UV region, the capacitance of Bi-doped thin films increased by 15%. SEM and EDX analysis revealed that the percentage of bismuth on the surface was dramatically increased with the increase of doped bismuth amount. On the other hand, various differences were observed on the surface images of doped and undoped films, serious differentiations were especially observed on the morphologic structure of 15% Bi-doped films

The structural and optical properties of gamma-FeOOH thin film grown with CBD method

gamma-FeOOH thin films were produced by Chemical Bath Deposition (CBD) method at pH: 5 onto amorphous glass substrates. Structural properties of gamma-FeOOH thin film were analyzed with X-ray diffraction (XRD). Chemical analysis and surface image of thin film were investigated with EDX, SEM, respectively. Optical properties were investigated via UV-VIS spectrophotometer. gamma-FeOOH (lepidocrocite) crystal is orthorhombic structure and the XRD peak corresponding to the gamma-FeOOH is enhanced to (1 1 1) plane. The allowed direct and allowed indirect optical band gaps (Eg), optical transmission (T%), reflectivity (R%), absorption, refraction index (n), extinction coefficient (k), dielectric constant (epsilon) of the thin film were found to be 2.00 and 1.63 eV, 36.39 %, 24.86 %, 0.43, 2.98, 0.03 and 1.76, respectively

Synthesis and characterization of GO/IrO2 thin film supercapacitor

Graphene oxide - Iridium Oxide structures show high capacitance performance potential in terms of applications in supercapacitors. The scope of this study is synthesizing GO via Hummers Method and use it for the coating of various substrates. Accordingly, various supercapacitors in the form of thin film, namely glass/GO/IrO2, PMMA/GO/IrO2, ETO/GO/IrO2 and ITO/GO/IrO2, were successfully produced via chemical bath deposition (CBD) on various substrates. Structural characterizations were analyzed through SEM, XRD, ATR, UV and AFM. In addition, I-V and C-V characteristics were investigated and energy densities were calculated for a voltage range (from -0.2 to 1.2 V), at scanning speed of 25 mV/s, 50 mV/s, 75mV/s and 100mV/s. It was found that all thin films supercapacitors structures (glass/GO/IrO2, PMMA/GO/IrO2, FTO/GO/IrO2 and ITO/GO/IrO2) reached their maximum capacitance values at the scanning rate of 25 mV/s, which were found to be 551.7 F/g, 837.7 F/g, 433.2 F/g and 569.7 F/g; and the energy intensities were calculated as 15.3Wh/kg, 34.9Wh/kg, 7.2Wh/kg and 12.64 Wh/kg respectively. (c) 2018 Elsevier B.V. All rights reserved

Synthesis and Characterization of GO/V2O5 Thin Film Supercapacitor

For potential applications in supercapacitors, Graphene oxide - Vanadium oxide structures exhibit high capacitance performance. In this study, GO was synthesized by Hummers Method and coated on substrate materials. Then, thin film supercapacitors glass/GO/VO, PMMA/GO/VO, FTO/ GO/VO and ITO/ GO/VO were fabricated successfully by chemical bath deposition method (CBD). Structural characterizations were investigated by SEM, XRD, FTIR, UV-VIS and AFM. I-V and C-s-V characteristics were investigated and energy densities were calculated at voltage range (from -0.2 to 1.2 V) at scanning potential 25, 50, 75 and 100 mV/s. At the scanning rate of 25 mV/s, the maximum capacitance values for glass/GO/VO, PMMA/GO/VO, FTO/GO/VO and ITO/GO/VO thin film supercapacitors structures were 880 F/g, 806.6 F/g, 949.6 F/g and 563.2 F/g; and the energy intensities were calculated as 85.4 W h/kg, 44.8 W h/kg, 15.78 W h/kg, 23.4 W h/kg, respectively

Reduced graphene oxide/molybdenum oxide thin films and its' capacitance properties: Different substrates effect

This study used the Chemical Bath Deposition method, which is quite simple and cheap, to produce GO/MoO3 nanocomposite, whose high capacitance properties draws attention. The Graphene oxide solution is prepared by synthesizing through the Hummer Method. These two materials were left to grow slowly on their own so that GO/MoO3 nanocomposite structures form thin films on Glass, Poly(methyl methacrylate), Fluorine tin oxide, and indium tin oxide substrates. The surface and structural properties of these GO/MoO3 nanocomposite structures were characterized by Scanning Electron Microscopy, Energy Dispersive X-ray, FTIR, X-ray diffraction, and Atomic Force Microscopy. The nanocomposites' capacitance properties produced on different substrates were measured in -0.2 - 0.2 V at different scan rates. As a result, the highest specific capacitance values were achieved at 25 mV/s scan rate, as 587 F/g, for Poly(methyl methacrylate)