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Kavan L.,J. Heyrovsky Institute of Physical Chemistry
Topics in Current Chemistry | Year: 2014

Fullerenes, carbon nanotubes, nanodiamond, and graphene find various applications in the development of solar cells, including dye sensitized solar cells. Nanocarbons can be used as (1) active light-absorbing component, (2) current collector, (3) photoanode additive, or (4) counter electrode. Graphene-based materials have attracted considerable interest for catalytic counter electrodes, particularly in state-of-the-art dye sensitized solar cells with Co-mediators. The understanding of electrochemical charge-transfer at carbon surfaces is key to optimization of these solar cells, but the electrocatalysis on carbon surfaces is still a subject of conflicting debate. Due to the rich palette of problems at the interface of nanocarbons and photovoltaics, this review is selective rather than comprehensive. Its motivation was to highlight selected prospective inputs from nanocarbon science towards the development of novel dye sensitized solar cells with improved efficiency, durability, and cost. © 2014 Springer-Verlag Berlin Heidelberg. Source

Kavan L.,J. Heyrovsky Institute of Physical Chemistry
Journal of Solid State Electrochemistry | Year: 2014

This article presents a critical discussion of selected structural aspects of electrochemical Li-insertion into TiO2 (anatase). Recent works are reviewed (almost half of the cited works is from 2010+) with a special attention to the crystal-face-specific phenomena, Raman spectroscopy, and single-crystal and nanocrystalline electrodes. The benefits of isotopic labeling are highlighted for the in-depth understanding of Raman spectra and the Raman spectroelectrochemistry of Li-insertion. The persisting open questions and contradictory issues in the field are discussed too. © 2014 Springer-Verlag Berlin Heidelberg. Source

Spanel P.,J. Heyrovsky Institute of Physical Chemistry | Smith D.,Keele University
Mass Spectrometry Reviews | Year: 2011

The development of selected ion flow tube mass spectrometry, SIFT-MS, is described from its inception as the modified very large SIFT instruments used to demonstrate the feasibility of SIFT-MS as an analytical technique, towards the smaller but bulky transportable instruments and finally to the current smallest Profile 3 instruments that have been located in various places, including hospitals and schools to obtain on-line breath analyses. The essential physics and engineering principles are discussed, which must be appreciated to design and construct a SIFT-MS instrument. The versatility and sensitivity of the Profile 3 instrument is illustrated by typical mass spectra obtained using the three precursor ions H3O+, NO+ and O 2 +•, and the need to account for differential ionic diffusion and mass discrimination in the analytical algorithms is emphasized to obtain accurate trace gas analyses. The performance of the Profile 3 instrument is illustrated by the results of several pilot studies, including (i) on-line real time quantification of several breath metabolites for cohorts of healthy adults and children, which have provided representative concentration/population distributions, and the comparative analyses of breath exhaled via the mouth and nose that identify systemic and orally-generated compounds, (ii) the enhancement of breath metabolites by drug ingestion, (iii) the identification of HCN as a marker of Pseudomonas colonization of the airways and (iv) emission of volatile compounds from urine, especially ketone bodies, and from skin. Some very recent developments are discussed, including the quantification of carbon dioxide in breath and the combination of SIFT-MS with GC and ATD, and their significance. Finally, prospects for future SIFT-MS developments are alluded to. Copyright © 2010 Wiley Periodicals, Inc. Source

Cejka J.,J. Heyrovsky Institute of Physical Chemistry
Topics in Catalysis | Year: 2010

This overview covers the recent achievements in the application of mesoporous molecular sieves as catalysts and catalyst supports. Main structural and textural features are outlined in relation to the novel synthesis approaches of mesoporous molecular sieves and understanding of their properties. For application of mesoporous molecular sieves as catalysts different ways of introduction of active sites on their surfaces are provided. The main part describes selected catalytic reactions catalyzed by mesoporous molecular sieves focused on very recent papers. The examples include metathesis, acylation reactions, C-C coupling reactions of Heck and Suzuki types, base-catalyzed reactions (Knoevenagel and Michael additions, Claisen-Schmidt condensation, Tischenko reaction) and last but not least immobilization of organometallic complexes for different catalytic applications including chiral catalysts. © 2009 Springer Science+Business Media, LLC. Source

Samec Z.,J. Heyrovsky Institute of Physical Chemistry
Electrochimica Acta | Year: 2012

This note provides a brief account of the theoretical and experimental achievements in the study of the interface between two immiscible electrolytes, in particular of its structure and dynamics, and the charge transfer kinetics, including the most remarkable results that have been obtained in the last five years. Perspective topics for the future research in this area are outlined. © 2012 Elsevier Ltd. Source

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