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Benzendicarboxylic acid (BDC)-based metal–organic frameworks (MOFs) have been widely utilized in various applications, including supercapacitor electrode materials. Manganese and copper have solid diamond frames formed with BDC linkers among transition metals chosen for MOF formation. They have shown the possibility to enlarge capacitance at different combinations of MOFs and polyaniline (PANI). Herein, reduced graphene oxide (rGO) was used as the matrix to fabricate electrochemical double-layer SCs. PANI and Mn/Cu-MOF's effect on the properties of electrode materials was investigated through electrochemical analysis. As a result, the highest specific capacitance of about 276 F/g at a current density of 0.5 A/g was obtained for rGO/Cu-MOF@PANI composite.

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Two new ullazine-based organic dyes have been synthesized for applications in nanocrystalline TiO 2 -based dye-sensitized solar cells (DSSCs). Overall conversion efficiencies up to 3.63% were obtained for DSSCs based on these dyes. The dye with a tert-butyl antenna exhibited a higher and redshifted absorption pattern resulting in increased light-harvesting property. Compared to the unsubstituted dye, the photocurrent density, open-circuit photovoltage and overall power conversion efficiency (PCE) of solar cells based on the tert-butyl substituted dye are improved. The decreased PCE of the solar cell based on unsubstituted dye results mainly from the increased recombination rate and decreased electron lifetime, as evidenced from impedance and photovoltage decay measurements. Density functional theory (DFT) and time-dependent DFT calculations were performed to predict the geometries, electronic structure, and the optical and electrochemical properties of the dyes.

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Linear actuators based on polypyrrole (PPy) are envisaged to have only one ion that triggers the actuation direction, either at oxidation (anion-driven) or at reduction (cation-driven). PPy doped with dodecylbenzenesulfonate (PPy/DBS) is the most common applied conducting polymer having cation-driven actuation in aqueous solvent and mainly anion-driven actuation in an organic electrolyte. It is somehow desired to have an actuator that is independent of the applied solvent in the same actuation direction. In this research we made PPy/DBS with the addition of phosphorus tungsten acid, forming PPyPT films, as well with included carbide derived carbon (CDC) resulting in PPyCDC films. The solvent in electropolymerization was changed from an aqueous ethylene glycol mixture to pure EG forming PPyPT-EG and PPyCDC-EG composites. Our goal in this study was to investigate the linear actuation properties of PPy composites applying sodium perchlorate in aqueous (NaClO4-aq) and propylene carbonate (NaClO4-PC) electrolytes. Cyclic voltammetry and square potential steps in combination with electro-chemo-mechanical-deformation (ECMD) measurements of PPy composite films were performed. The PPyPT and PPyCDC had mixed ion-actuation in NaClO4-PC while in NaClO4-aq expansion at reduction (cation-driven) was observed. Those novel PPy composites electropolymerized in EG solvent showed independently which solvent applied mainly expansion at reduction (cation-driven actuator). Chronopotentiometric measurements were performed on all composites, revealing excellent specific capacitance up to 190 F g−1 for PPyCDC-EG (best capacitance retention of 90% after 1000 cycles) and 130 F g−1 for PPyPT-EG in aqueous electrolyte. The films were characterized by scanning electron microscopy (SEM), Raman, Fourier-transform infrared (FTIR) and energy dispersive X-ray spectroscopy (EDX).