Ruthenium

About: Ruthenium is a research topic. Over the lifetime, 40184 publications have been published within this topic receiving 996514 citations. The topic is also known as: Ru & element 44.

A stable quasi-solid-state dye-sensitized solar cell with an amphiphilic ruthenium sensitizer and polymer gel electrolyte.

Abstract: Dye-sensitized nanocrystalline solar cells (DSC) have received considerable attention as a cost-effective alternative to conventional solar cells. One of the main factors that has hampered widespread practical use of DSC is the poor thermostability encountered so far with these devices. Here we show a DSC with unprecedented stable performance under both thermal stress and soaking with light, matching the durability criteria applied to silicon solar cells for outdoor applications. The cell uses the amphiphilic ruthenium sensitizer cis-RuLL'(SCN)(2) (L = 4,4'-dicarboxylic acid-2,2'-bipyridine, L' = 4,4'-dinonyl-2,2'-bipyridine) in conjunction with a quasi-solid-state polymer gel electrolyte, reaching an efficiency of >6% in full sunlight (air mass 1.5, 100 mW cm(-2)). A convenient and versatile new route is reported for the synthesis of the heteroleptic ruthenium complex, which plays a key role in achieving the high-temperature stability. Ultramicroelectrode voltammetric measurements show that the triiodide/iodide couple can perform charge transport freely in the polymer gel. The cell sustained heating for 1,000 h at 80 degrees C, maintaining 94% of its initial performance. The device also showed excellent stability under light soaking at 55 degrees C for 1,000 h in a solar simulator (100 mW cm(-2)) equipped with a ultraviolet filter. The present findings should foster widespread practical application of dye-sensitized solar cells.

A Bifunctional Nonprecious Metal Catalyst for Oxygen Reduction and Water Oxidation

Abstract: There is a growing interest in oxygen electrochemistry as conversions between O(2) and H(2)O play an important role in a variety of renewable energy technologies. The goal of this work is to develop active bifunctional catalyst materials for water oxidation and oxygen reduction. Drawing inspiration from a cubane-like CaMn(4)O(x), the biological catalyst found in the oxygen evolving center (OEC) in photosystem II, nanostructured manganese oxide surfaces were investigated for these reactions. Thin films of nanostructured manganese oxide were found to be active for both oxygen reduction and water oxidation, with similar overall oxygen electrode activity to the best known precious metal nanoparticle catalysts: platinum, ruthenium, and iridium. Physical and chemical characterization of the nanostructured Mn oxide bifunctional catalyst reveals an oxidation state of Mn(III), akin to one of the most commonly observed Mn oxidation states found in the OEC.

Ruthenium red and violet. I. Chemistry, purification, methods of use for electron microscopy and mechanism of action

Abstract: The properties of the inorganic dye ruthenium red are presented with emphasis upon its use for electron microscopy of cells and tissues. Although commercial ruthenium red often can be used directly, it always contains various impurities and by-products. One of these, termed ruthenium violet, can be isolated and is useful by itself. Absorption spectra of the ruthenium dyes and common impurities are given so that an assay is possible for any sample. Convenient fixative recipes containing ruthenium red or violet are provided together with constraints necessary for a reliable reaction to label extracellular acidic mucosubstances. Perfusion was not successful. The specificity of the ruthenium red reaction was evaluated by spot testing with 57 substances, and by titration with chemically defined pectins. The results indicate that ruthenium red, as a hexavalent cation, precipitates a large variety of polyanions by ionic interaction, and that its classical reaction with pectin is typical rather than specific. New data are presented regarding its reaction with phospholipids. For electron microscopy, a further reaction with OsO4 amplifies the feeble electron density, which is the counterpart of its intense optical labeling, to a practical level resulting in strong contrast. An hypothesis is presented for the mechanism underlying this intensification.