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Bice S Martincigh, Moses A Ollengo
The photostabilizing ability of grape seed extract on three common sunscreen absorbers: 2-ethylhexyl-p-methoxcinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composition of the grape seed extract was determined by GC-MS and HPLC-MS and the major secondary metabolites were found to be epicatechin and catechin. Exposure of the extract to UV radiation increased the UV absorption capacity of the extract...
October 19, 2016: Photochemistry and Photobiology
Nobuo Kimizuka, Nobuhiro Yanai, Masa-Aki Morikawa
Self-assembly of functional molecules into ordered molecular assemblies and fulfillment of potentials unique to their nano-to-mesoscopic structures have been one of the central challenges in chemistry. This Feature Article provides an overview of recent progress in the field of molecular self-assembly with the focus on the triplet-triplet annihilation-based photon upconversion (TTA-UC) and supramolecular storage of photon energy. Based on the integration of molecular self-assembly and photon energy harvesting, triplet energy migration-based TTA-UC has been achieved in varied molecular systems...
October 19, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Bhaskar Dudem, Yeong Hwan Ko, Jung Woo Leem, Joo Ho Lim, Jae Su Yu
We report the hierarchical nano/micro architectured (HNMA)-polydimethylsiloxane (PDMS) film-based hybrid energy cells with multi-functionality to simultaneously harvest mechanical, solar, and wind energies. These films consist of nano/micro dual-scale architectures (i.e., nanonipples on inverted micro pyramidal arrays) on the PDMS surface. The HNMA-PDMS is replicable by a facile and cost-effective soft imprint lithography (SIL) using a nanoporous anodic alumina oxide (AAO) film formed on the micro-pyramidal (MP) structured silicon substrate...
October 19, 2016: ACS Applied Materials & Interfaces
Atanu Jana, Masatoshi Ishida, Jung Su Park, Steffen Bähring, Jan O Jeppesen, Jonathan L Sessler
After the epochal discovery of the "organic metal", namely, tetrathiafulvalene (TTF)-7,7,8,8-tetracyano-p-quinodimethane (TCNQ) dyad in 1973, scientists have made efforts to derivatize TTF for constructing various supramolecular architectures to control the charge-transfer processes by adjusting the donor-acceptor strength of the dyads for numerous applications. The interesting inherent electronic donor properties of TTFs control the overall electrochemical properties of the supramolecular structures, leading to the construction of highly efficient optoelectronic materials, photovoltaic solar cells, organic field-effect transistors, and optical sensors...
October 18, 2016: Chemical Reviews
Teng-Fei Lu, Wei Li, Jie Chen, Fu-Quan Bai, Jian Wang, Ling-Jun He, Hong-Xing Zhang
In this work, we designed three dyes (Ru1, Ru2, and Ru3) by modifying the square-planar quadridentate ligand of the experimental Ru(ii) complex K1, [RuL(trans-NCS)2] with L = dimethyl-6,60-bis(methyl-2-pyridylamino)-2,20-bipyridine-4,40-dicarboxylate, from a theoretical viewpoint. As is known, K1 shows obvious advantages over the famous dye N749 in light absorption ability because of its highly conjugated ancillary ligands. Density functional theory and time-dependent density functional theory methods were used to determine the geometrical structures, electronic structures and absorption spectra of the dye complexes...
October 18, 2016: Physical Chemistry Chemical Physics: PCCP
Chong Liu, Jiandong Fan, Hongliang Li, Cuiling Zhang, Yaohua Mai
Despite organometal halide perovskite solar cells have recently exhibited a significant leap in efficiency, the Sn-based perovskite solar cells still suffer from low efficiency. Here, a series homogeneous CH3NH3Pb(1-x)SnxI3 (0 ≤ x ≤ 1) perovskite thin films with full coverage were obtained via solvent engineering. In particular, the intermediate complexes of PbI2/(SnI2)∙(DMSO)x were proved to retard the crystallization of CH3NH3SnI3, thus allowing the realization of high quality Sn-introduced perovskite thin films...
October 18, 2016: Scientific Reports
Qiufang Gong, Yu Wang, Qi Hu, Jigang Zhou, Renfei Feng, Paul N Duchesne, Peng Zhang, Fengjiao Chen, Na Han, Yafei Li, Chuanhong Jin, Yanguang Li, Shuit-Tong Lee
Earlier research has been primarily focused on WC as one of the most promising earth-abundant electrocatalysts for hydrogen evolution reaction (HER), whereas the other compound in this carbide family-W2C-has received far less attention. Our theoretical calculations suggest that such a focus is misplaced and W2C is potentially more HER-active than WC. Nevertheless, the preparation of phase pure and sintering-free W2C nanostructures represents a formidable challenge. Here we develop an improved carburization method and successfully prepare ultrasmall and phase-pure W2C nanoparticles...
October 18, 2016: Nature Communications
Lin Ma, Feng Hao, Constantinos C Stoumpos, Brian T Phelan, Michael R Wasielewski, Mercouri G Kanatzidis
The dynamics of photoexcited lead-free perovskite films, CH3NH3SnI3, were studied using broadband transient absorption (TA) and time-resolved fluorescence (TRF) spectroscopy. Similar to its lead analogue CH3NH3PbI3, we show that free carrier (electrons and holes) recombination is also the dominant relaxation pathway in CH3NH3SnI3 films. The slow hot carrier relaxation time is 0.5 ps. Long carrier diffusion lengths for electrons (279 ± 88 nm) and holes (193 ± 46 nm) were obtained from fluorescence quenching measurements...
October 17, 2016: Journal of the American Chemical Society
Yasemin Saygili, Magnus Söderberg, Norman Pellet, Fabrizio Giordano, Yiming Cao, Ana B Munoz-Garcia, Shaik Mohammed Zakeeruddin, Nick Vlachopoulos, Michele Pavone, Gerrit Boschloo, Ladislav Kavan, Jacques-E Moser, Michael Grätzel, Anders Hagfeldt, Marina Freitag
Redox mediators play a major role determining the photocurrent and the photovoltage in dye-sensitized solar cells (DSCs). To maintain the photocurrent, the reduction of oxidized dye by the redox mediator should be significantly faster than the back electron transfer between TiO2 and the oxidized dye. The driving force for dye regeneration with the redox mediator should be sufficiently low to provide high photovoltages. With our introduction of new copper complexes as promising redox mediators in DSCs both criteria are satisfied to enhance power conversion efficiencies...
October 17, 2016: Journal of the American Chemical Society
Giles E Eperon, David Moerman, David S Ginger
We use high-resolution, spatially resolved, laser beam induced current, confocal photoluminescence, and photoconductive atomic force microscopy (pcAFM) measurements to correlate local solar cell performance with spatially heterogeneous local material properties in methylammonium lead triiodide (CH3NH3PbI3) perovskite solar cells. We find that, for this material and device architecture, the photocurrent heterogeneity measured via pcAFM on devices missing a top selective contact with traditional Au-coated tips is significantly larger than the photocurrent heterogeneity observed in full devices with both electron- and hole-selective extraction layers, indicating that extraction barriers at the Au/perovskite interface are ameliorated by deposition of the organic charge extraction layer...
October 17, 2016: ACS Nano
Ke Chen, Qin Hu, Tanghao Liu, Lichen Zhao, Deying Luo, Jiang Wu, Yifei Zhang, Wei Zhang, Feng Liu, Thomas P Russell, Rui Zhu, Qihuang Gong
The charge-carrier balance strategy by interface engineering is employed to optimize the charge-carrier transport in inverted planar heterojunction perovskite solar cells. N,N-Dimethylformamide-treated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) and poly(methyl methacrylate)-modified PCBM are utilized as the hole and electron selective contacts, respectively, leading to a high power conversion efficiency of 18.72%.
October 17, 2016: Advanced Materials
Bert Conings, Aslihan Babayigit, Matthew T Klug, Sai Bai, Nicolas Gauquelin, Nobuya Sakai, Jacob Tse-Wei Wang, Johan Verbeeck, Hans-Gerd Boyen, Henry J Snaith
A robust and expedient gas quenching method is developed for the solution deposition of hybrid perovskite thin films. The method offers a reliable standard practice for the fabrication of a non-exhaustive variety of perovskites exhibiting excellent film morphology and commensurate high performance in both regular and inverted structured solar cell architectures.
October 17, 2016: Advanced Materials
Shuguang Chen, Hailang Jia, Mengxi Zheng, Kang Shen, Hegen Zheng
Herein we prepare four novel D-π-A dyes based on triphenylamine (ZHG1, ZHG2, ZHG3 and ZHG4) by modifying the π-bridges. Compared with ZHG1, the power conversion efficiency (PCE) of ZHG2 is improved to 6.1% after the introduction of ethynyl. But further extension of the conjugation of the π-bridges by introducing the chromophore 4,8-bis(n-octyloxy)-benzo[1,2-b:4,5-b']dithiophene (BDT) into ZHG3 conversely decreases the PCE to 4.6%. Improving the coplanarity by replacing cyclobenzene with thiophene in ZHG4 after introducing BDT further decreases the PCE of ZHG4 to 4...
October 17, 2016: Physical Chemistry Chemical Physics: PCCP
Balakrishna Ananthoju, Jeotikanta Mohapatra, Manoj K Jangid, D Bahadur, N V Medhekar, M Aslam
Cations and anions are replaced with Fe, Mn, and Se in CZTS in order to control the formations of the secondary phase, the band gap, and the micro structure of Cu2ZnSnS4. We demonstrate a simplified synthesis strategy for a range of quaternary chalcogenide nanoparticles such as Cu2ZnSnS4 (CZTS), Cu2FeSnS4 (CFTS), Cu2MnSnS4 (CMTS), Cu2ZnSnSe4 (CZTSe), and Cu2ZnSn(S0.5Se0.5)4 (CZTSSe) by thermolysis of metal chloride precursors using long chain amine molecules. It is observed that the crystal structure, band gap and micro structure of the CZTS thin films are affected by the substitution of anion/cations...
October 17, 2016: Scientific Reports
Yang Yang, Di Xu, Qingyong Wu, Peng Diao
Solar powered hydrogen evolution reaction (HER) is one of the key reactions in solar-to-chemical energy conversion. It is desirable to develop photocathodic materials that exhibit high activity toward photoelectrochemical (PEC) HER at more positive potentials because a higher potential means a lower overpotential for HER. In this work, the Cu2O/CuO bilayered composites were prepared by a facile method that involved an electrodeposition and a subsequent thermal oxidation. The resulting Cu2O/CuO bilayered composites exhibited a surprisingly high activity and good stability toward PEC HER, expecially at high potentials in alkaline solution...
October 17, 2016: Scientific Reports
Naoki Oiso, Tomohiko Narita, Akira Kawada
No abstract text is available yet for this article.
October 17, 2016: European Journal of Dermatology: EJD
Angela N Fioretti, Craig P Schwartz, John Vinson, Dennis Nordlund, David Prendergast, Adele C Tamboli, Christopher M Caskey, Filip Tuomisto, Florence Linez, Steven T Christensen, Eric S Toberer, Stephan Lany, Andriy Zakutayev
Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu3N thin films...
May 14, 2016: Journal of Applied Physics
Jakub Trawiński, Robert Skibiński
The photolytic and photocatalytic transformation of tiapride with the use of TiO2 and H2O2 was investigated. A novel micro-scale method for simultaneous irradiation with simulated full solar spectrum of multiple samples in photostability chamber was proposed. RP-UHPLC-DAD coupled with ESI-Q-TOF mass spectrometer was used for the quantitative and qualitative analysis of the processes. Quantitative method was fully validated, and kinetic parameters of tiapride photodegradation were compared. Structures of twenty-one photoproducts as well as phototransformation pathways were proposed...
October 6, 2016: Journal of Hazardous Materials
A Carratalá, R Moreno-González, V M León
The occurrence and seasonal distribution of polycyclic aromatic hydrocarbons (PAHs) and legacy and current-use pesticides (CUPs) in air were characterized around the Mar Menor lagoon using both active and passive sampling devices. The seasonal distribution of these pollutants was determined at 6 points using passive samplers. Passive sampler sampling rates were estimated for all detected analytes using an active sampler, considering preferentially winter data, due to probable losses in active sampling during summer (high temperatures and solar irradiation)...
October 13, 2016: Chemosphere
Dong Jin Lee, G Mohan Kumar, P Ilanchezhiyan, Jae-Chul Lee, Sung Ryong Ryu, Tae Won Kang
Nowadays, solid-state inorganic-organic hybrid solar cells based on one-dimensional (1D) inorganic semiconducting nanostructures and organic polymers are believed to offer convincing solutions for the realm of next generation solar cells. In this regard, 1D ZnCdS nanowire (NW) arrays were fabricated on transparent conducting substrates through a catalyst free co-evaporation method and their wurtzite structural characteristics, 1D morphological layout and valence state/composition were studied in detail using X-ray diffraction, high-resolution electron microscopy and X-ray photoelectron spectroscopy, respectively...
October 5, 2016: Journal of Colloid and Interface Science
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