Improvement in photovoltaic performance of rutile-phased TiO2 nanorod/nanoflower-based dye-sensitized solar cell

An improved dye-sensitized solar cell (DSC) of rutile-phased titanium dioxide (TiO2) electrode with increased power conversion efficiency was successfully fabricated. Rutile-phased TiO2 nanorods and nanoflowers were grown directly on fluorine-doped SnO2 (FTO) by simple aqueous chemical growth technique using one-step hydrothermal process. The solution was prepared by mixing hydrochloric acid, deionized water, and titanium butoxide used as precursor. In the preparation of DSC, both TiO2 nanorods and nanoflowers, platinum (Pt), ruthenium dye N719, and DPMII electrolyte were used as photoelectrode, counter electrode, dye solution, and liquid electrolyte, respectively. The prepared rutile-phased TiO2 nanorods and nanoflowers samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The DSCs were fabricated based on the rutile-phased titanium dioxide nanorod and nanoflower photoelectrodes. For their energy conversion efficiency, I-V characteristics and electrochemical impedance spectroscopy were studied. We also investigated the effect of cetyltrimethylammonium bromide (CTAB) reaction times 2, 5, and 10 h in the preparation of rutile-phased TiO2 nanoflowers for DSC. CTAB is one of the capping agents that cover the refine surface of nanoparticles and prevent them from coagulation or aggregation. In our final result, the combination of rutile-phased TiO2 nanorod- and nanoflower-based DSCs showed best efficiency at approximately 3.11% due to its good electron transport of TiO2 nanorods and increased surface area by the TiO2 nanoflowers that had increased dye absorption

Cycling Performance of Nanocrystalline<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mtext>LiMn</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mtext>4</mml:mtext></mml:msub></mml:math>Thin Films via Electrophoresis

The present study demonstrates a novel approach by which titanium foils coated with LiMn2O4nanocrystals can be processed into a high-surface-area electrode for rechargeable batteries. A detailed study has been performed to elucidate how surface morphology and redox reaction behaviors underlying these electrodes impact the cyclic and capacity behavior. These nanocrystals were synthesized by in situ sintering and exhibited a uniform size of ∼55 nm. A direct deposition technique based on electrophoresis is employed to coat LiMn2O4nanocrystals onto titanium substrates. From the analysis of the relevant electrochemical parameters, an intrinsic correlation between the cyclability and particle size has been deduced and explained in accordance with the Li intercalation/deintercalation process. Depending on the particle size incorporated on these electrodes, it is seen that in terms of capacitance fading, for nanoparticles cyclability is better than their micron-sized counterparts. It has been shown that electrodes based on such nanocrystalline thin film system can allow significant room for improvement in the cyclic performance at the electrode/electrolyte interface.</jats:p

MnO₂ nano/micro hybrids for supercapacitors: “Nano's Envy, Micro's pride”

The present study provides the first reports on a low temperature molten salt route which can generate unique architecture of MnO2 nanospikes arrayed in a peculiar fashion to form micron sized ball morphology.</p

Synthesis, characterization and rate capability performance of the micro-porous MnO2 nanowires as cathode material in lithium batteries

A peculiar architecture of one-dimensional MnO2 nanowires was synthesized by an optimized hydrothermal route and has been lucratively exploited to fabricate highly efficient microporous electrode overlays for lithium batteries. These fabricated electrodes comprised of interconnected nanoscale units with wire-shaped profile which exhibits high aspect ratio in the order of 102. Their outstanding intercalation/de-intercalation prerogatives have also been studied to fabricate lithium coin cells which revealed a significant specific capacity and power density of 251 mAh g-1 and 200 W kg-1, respectively. A detailed electrochemical study was performed to elucidate how surface morphology and redox reaction behaviors underlying these electrodes influence the cyclic behavior of the electrode. Rate capability tests at different C-rates were performed to evaluate the capacity and cycling performance of these coin cells