In this study the effect of the purification of electrolyte material on the performance and long-term stability of dye-sensitized solar cells is investigated. The combined effect of purifying all the electrolyte materials has been examined, as has the effect of purifying each compound to identify those compounds worth purifying and to eliminate unnecessary production steps on an industrial scale. Statistical methods were employed to draw statistically significant conclusions from the experimental results. No effect on the initial cell performance is found in this study. The purity of the electrolyte solvent (here methoxypropionitrile) is shown to have a remarkable effect on the cell lifetime: it could even double when the cell is properly purified. It is shown that exposing the cell to even relatively small amounts of UV light resulted in cell degradation through electrolyte bleaching during a 1000 hour aging test. Here the impurities in the electrolyte solvent lead to an almost doubled rate of electrolyte bleaching under UV light. Dye-sensitized solar cells (DSSC) have the potential to become a low-cost alternative to silicon solar cells in the future. They can be made out of sustainable materials, they have a wide application area, and they are on the threshold of large-scale production.1 They are also efficient: an 11.9% efficiency record for DSSCs has been achieved.2 At the moment one of the main challenges is the cell stability. DSSC stability for approximately 20 years in outdoor conditions is an essential prerequisite for the introduction of DSSCs into the wide commercial market, e.g., in the form of building-integrated panels. The structure of DSSCs is quite complicated and unfortunately the components tend to age when the DSSC is exposed long-term to light, humidity, and extreme temperatures. 3,1,4,5,6,7,8 Material purification has been proposed to increase the stability of the cells.9-12 The use of highly pure materials is also regarded as an essential step in the preparation of most efficient cells. 13,10,14 The reported data do not, however, include direct comparisons of purified and unpurified materials, which would be essential for assessing the importance of material purification in cell fabrication. From the industrial point of view, material purification increases the production costs of the cells. Thus the necessity of material purification should be studied carefully, 1,15 just like any step that increases the complexity of the production. The objective of this study is to investigate if cell efficiency and stability increase as a result of the purification of the electrolyte material. The effect of the purification of all the electrolyte materials has been studied and the effect of each compound has been statistically compared and analyzed. The research continues in, 16 where the effect of dye purification on cell efficiency and lifetime is studied.It is still quite common in the field to utilize only a few tests, mainly IV curve measurements in aging studies, or to test the cells only at the...

The substrate scope in the dynamic kinetic resolution of secondary alcohols was studied by using 31 structurally different alcohols and isopropenyl acetate in the presence of dicarbonylchlorido(pentabenzylcyclopentadienyl)ruthenium and Candida antarctica lipase B (Novozym 435, CAL-B) in toluene. The enzyme and the ruthenium complex were shown to function in a highly compatible manner allowing the conversion of the racemic alcohols into the (R)-acetates

Dicarbonylchloro(pentabenzylcyclopentadienyl)ruthenium has been prepared and its structure confirmed by X‐ray analysis. This complex shows excellent catalytic activity and modest stability against air in racemization reactions of secondary alcohols. In Candida antarctica lipase B (CAL‐B) catalyzed dynamic kinetic resolution (DKR) of 1‐phenyl‐ and 1‐(furan‐2‐yl)ethanol compounds, the new complex shows improved performance as an alcohol racemization catalyst in comparison with its well‐known pentaphenylcyclopentadienyl analogue, hitherto considered as the leading catalyst candidate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Several half-sandwich complexes of ruthenium with cyclopenta[l]phenanthrenyl and cyclopenta[a]acenaphthylenyl ligands containing fused aromatic ring substituents on the cyclopentadienyl ring were prepared and characterized by NMR and X-ray crystallography. Activities of the complexes as racemization catalysts for secondary alcohols were preliminarily screened by using (S)-phenylethanol as the substrate. The catalytic activities of the fused-ring complexes depend strongly on the number of other substituents in the five-membered ring and are inferior to those reported earlier for chlorodicarbonyl(pentaphenylcyclopentadienyl)ruthenium, currently considered as the best catalyst candidate for dynamic kinetic resolution of secondary alcohols by combined enzyme/metal catalysis.