共查询到20条相似文献,搜索用时 0 毫秒
1.
Loiudice A Rizzo A De Marco L Belviso MR Caputo G Cozzoli PD Gigli G 《Physical chemistry chemical physics : PCCP》2012,14(11):3987-3995
We report on a novel approach to integrate colloidal anatase TiO(2) nanorods as key functional components into polymer bulk heterojunction (BHJ) photovoltaic devices by means of mild, all-solution-based processing techniques. The successful integration of colloidal nanoparticles in organic solar cells relies on the ability to remove the long chain insulating ligands, which indeed severely reduces the charge transport. To this aim we have exploited the concomitant mechanisms of UV-light-driven photocatalytic removal of adsorbed capping ligands and hydrophilicization of TiO(2) surfaces in both solid-state and liquid-phase conditions. We have demonstrated the successful integration of the UV-irradiated films and colloidal solutions of TiO(2) nanorods in inverted and conventional solar cell geometries, respectively. The inverted devices show a power conversion efficiency of 2.3% that is a ca. three times improvement over their corresponding cell counterparts incorporating untreated TiO(2), demonstrating the excellent electron-collecting property of the UV-irradiated TiO(2) films. The integration of UV-treated TiO(2) solutions in conventional devices results in doubled power conversion efficiency for the thinner active layer and in maximum power conversion efficiency of 2.8% for 110 nm thick devices. In addition, we have demonstrated, with the support of device characterizations and optical simulations, that the TiO(2) nanocrystal buffer layer acts both as electron-transporting/hole-blocking material and optical spacer. 相似文献
2.
Staniszewski A Ardo S Sun Y Castellano FN Meyer GJ 《Journal of the American Chemical Society》2008,130(35):11586-11587
After rapid photoinduced electron injection into TiO2 and regeneration by a donor, D, such as iodide or phenothiazine, sensitizers are present in an environment distinctly different from that prior to light absorption. Significantly, the absorption spectrum of the Ru(II) sensitizer in this new environment is one that is known to be less favorable for excited-state electron injection. The transient absorption features were found to report on photoinduced variations in the local electronic environment of the Ru(II) sensitizer-TiO2 interface that were induced by ion transfer. The data demonstrate that slow (micros to ms) cation transfer follows regeneration to yield the sensitizer that was initially photoexcited. 相似文献
3.
Jiang KJ Masaki N Xia JB Noda S Yanagida S 《Chemical communications (Cambridge, England)》2006,(23):2460-2462
A hydrophobic and 2-thiophen-2-yl-vinyl-conjugated ruthenium complex, cis-Ru(dhtbpy)(dcbpy)(NCS)2 [dhtbpy = 4,4'-di(hexylthienylvinyl)-2,2'-bipyridyl; dcbpy = 4,4'-dicarboxy-2,2'-bipyridyl], was newly designed, synthesized and applied successfully to sensitization of nanocrystalline TiO2-based solar cells, giving a conversion efficiency of 9.5% under irradiation with AM 1.5 solar light. 相似文献
4.
High surface area mesoporous titanium dioxide (TiO2) particles have been prepared by three different kinds of colloidal aphrons: colloidal gas aphrons, colloidal liquid aphrons, and colloidal emulsion aphrons (CEAs). The precipitate of amorphous TiO2 was prepared by hydrolysis, condensation, and polycondensation reaction of the precursor. The reaction took place under the effect of coulombic repulsion and electrostatic layers of multilayer surfactant molecules. TiO2 particles with various sizes were prepared with different molar ratio of titanium ion to surfactants, which were sodium lauryl sulfate (SDS), cetyltrimetyhlammonium bromide, triblock copolymer Pluronic P123, and triblock copolymer Pluronic F127. The synthesized samples were characterized by X-ray diffraction, Brunauer-Emmett-Teller analysis, N2 adsorption/desorption, and transmission electron microscopy. The mesoporous TiO2 prepared by CEAs method showed a high specific surface area of 224 m2/g with the total pore volume of 0.7751 cm3/g by using SDS as the membrane phase surfactant due to electrostatic attraction favors of anionic surfactant. The solar conversion efficiency of the cell made from TiO2 increases with the combination of increased surface area and total pore volume for higher amount of dye wetting and loading. 相似文献
5.
Jung HS Lee SW Kim JY Hong KS Lee YC Ko KH 《Journal of colloid and interface science》2004,279(2):479-483
TiO2 film for use as dye-sensitized solar cell was prepared using the TiO2 colloidal sols (unpeptized sol and peptized sol). The optical properties and photocurrent-voltage characteristics of the resultant films were investigated. The optical transmittance of TiO2 thin film prepared from the peptized colloidal sol was over 90%, while that of TiO2 film from the unpeptized sol was under 80%. The TiO2 photoelectrode prepared from the peptized colloidal sol showed low photoelectric conversion efficiency (eta), 1.30%, whereas the efficiency of photoelectrode from the unpeptized sol was 2.21%. The high optical transmittance and low conversion efficiency of TiO2 film from the peptized sol are discussed in terms of dense microstructure due to the drying nature of well-dispersed colloidal sol. 相似文献
6.
Zhu X Lu W Zhang Y Reed A Newton B Fan Z Yu H Ray PC Gao R 《Chemical communications (Cambridge, England)》2011,47(37):10311-10313
5,10,15,20-Tetrakis(N-(2-(1H-imidazol-4-yl)ethyl)benzamide)porphyrin produced twice as many singlet oxygen ((1)O(2)) molecules at pH 5.0 (quantum yield 0.53 ± 0.01) than at pH 7.4, whereas the (1)O(2) quenching rate was reduced by a factor of 2.5 for a pH change from 7.4 to 5.0. 相似文献
7.
Chongmu Lee Chanseok Hong Hohyeong Kim Jungwoo Kang Hong Mei Zheng 《Photochemistry and photobiology》2010,86(4):981-989
We report the photothermal properties as well as the in vitro cell test results of titanium oxide nanotubes (TiO2 NTs) as a potential therapeutic agent for cancer thermotherapy in combination with near-infrared (NIR) light. TiO2 NTs are found to have a higher photothermal effect upon exposure to NIR laser than Au nanoparticles and single-wall carbon nanotubes, which have also attracted considerable interest as therapeutic agents for cancer thermotherapy. The temperature increase of a TiO2 NT/NaCl suspension during NIR laser exposure is larger than that of a TiO2 NT/D.I. water suspension due to the heat generated by the formation of Na2TiF6. According to the in vitro cell test results the cells exposed to NIR laser without TiO2 NT treatment have a cell viability of 96.4%. Likewise, the cells treated with TiO2 NTs but not with NIR irradiation also have a cell viability of 98.2%. Combination of these two techniques, however, shows a cell viability of 1.35%. Also, the cell deaths are mostly due to necrosis but partly due to late apoptosis. These results suggest that TiO2 NTs can be used effectively as therapeutic agents for cancer thermotherapy due to their excellent photothermal properties and high biocompatibility. 相似文献
8.
Darka Mihailović Zoran Šaponjić Vesna Vodnik Branislav Potkonjak Petar Jovančić Jovan M. Nedeljković Maja Radetić 《先进技术聚合物》2011,22(12):2244-2249
This study is aimed to highlight the possibility of engineering the multifunctional textile nanocomposite material based on the polyester (PES) fabric modified with colloidal Ag and TiO2 nanoparticles (NPs). The effects of concentration of NPs as well as the order of Ag and TiO2 NPs loading on antimicrobial, UV protective, and photocatalytic properties of PES fabrics were examined. The antimicrobial activity of differently modified PES fabrics was tested against Gram‐negative bacterium Escherichia coli, Gram‐positive bacterium Staphylococcus aureus, and fungus Candida albicans. The concentration of Ag colloid and the order of Ag and TiO2 NPs loading considerably affected the antimicrobial efficiency of PES fabrics. The fabrics provided maximum UV protection upon surface modification with Ag and TiO2 NPs. Ag NPs enhanced Ag NPs enhanced the photodegradation activity of TiO2 NPs and total photodegradation of methylene blue was achieved after 24 hr of UV illumination. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
9.
Photocatalytic paper encompasses a range of materials based on paper and nonwoven fabrics which performs a function based on the light-activated catalytic activity of colloidal TiO(2). The literature describing photocatalytic paper is surveyed, including mechanisms, applications, limitations and future opportunities. The technology is in its infancy with less than 10 patents and as many scientific publications appearing over the last decade. The main applications described are the destruction of organic molecules (mineralization) and photo-disinfection (sterilization). These disclosures build upon a much larger literature describing photochemical properties of TiO(2) both supported on non-cellulose substrates or simply as suspended particles in water or air. Current photocatalytic paper developments include methods to fix TiO(2) to cellulose substrates to minimize photochemical damage to the paper. Another theme is the use of multiple approaches, such as zeolites, for enhanced mineralization, and metals, such as silver and copper, for enhanced photocatalytic disinfection. 相似文献
10.
Akhtaruzzaman M Islam A Yang F Asao N Kwon E Singh SP Han L Yamamoto Y 《Chemical communications (Cambridge, England)》2011,47(45):12400-12402
A novel donor-π-spacer-acceptor type organic dye (AK01) bearing a phenylenevinylene-conjugated system and a derivative of indoline donor was synthesized for dye-sensitized solar cells. AK01 showed panchromatic TiO(2) sensitization with high overall conversion efficiency of 6.2% under AM 1.5 illumination (100 mW cm(-2)). 相似文献
11.
Bryan JD Heald SM Chambers SA Gamelin DR 《Journal of the American Chemical Society》2004,126(37):11640-11647
Colloidal cobalt-doped TiO(2) (anatase) nanocrystals were synthesized and studied by electronic absorption, magnetic circular dichroism, transmission electron microscopy, magnetic susceptibility, cobalt K-shell X-ray absorption spectroscopy, and extended X-ray absorption fine structure measurements. The nanocrystals were paramagnetic when isolated by surface-passivating ligands, weakly ferromagnetic (M(s) approximately 1.5 x 10(-)(3) micro(B)/Co(2+) at 300 K) when aggregated, and strongly ferromagnetic (up to M(s) = 1.9 micro(B)/Co(2+) at 300 K) when spin-coated into nanocrystalline films. X-ray absorption data reveal that cobalt is in the Co(2+) oxidation state in all samples. In addition to providing strong experimental support for the existence of intrinsic ferromagnetism in cobalt-doped TiO(2), these results demonstrate the possibility of using colloidal TiO(2) diluted magnetic semiconductor nanocrystals as building blocks for assembly of ferromagnetic semiconductor nanostructures with potential spintronics applications. 相似文献
12.
Nika Veronovski Patrizia Andreozzi Camillo La Mesa Majda Sfiligoj-Smole Volker Ribitsch 《Colloid and polymer science》2010,288(4):387-394
Photocatalytically active TiO2 P25 nanoparticles, widely used for practical applications, were investigated. The nominal size of TiO2 P25 nanoparticles is 21 nm, but they easily agglomerate in aqueous media, depending on pH and ionic strength. TiO2 P25 aqueous dispersions were stabilized by alkanediyl-α,ω-bis-N-dodecyl-N, N′-dimethyl-ammonium bromide, cationic Gemini surfactant. The optimal conditions required to obtain stable dispersions, without
formation of large agglomerates, were experienced. The stabilization of TiO2 P25 nanoparticles by cationic Gemini surfactant was investigated in some details. Different amounts of Gemini surfactant
were used, at concentrations between 1.0 and 250 × 10−6 mol L−1, well below the critical micelle concentration. Dynamic light scattering and zeta potential analyses estimated the particle
size and the dispersions stability. When the proper amount of Gemini surfactant was used, the resulting nanoparticles were
still poly-disperse, but large agglomerates disappeared and were remarkably redispersible. 相似文献
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14.
Ashcroft JM Gu W Zhang T Hughes SM Hartman KB Hofmann C Kanaras AG Kilcoyne DA Le Gros M Yin Y Alivisatos AP Larabell CA 《Chemical communications (Cambridge, England)》2008,(21):2471-2473
This communication reports the development of a TiO2-streptavidin nanoconjugate as a new biological label for X-ray bio-imaging applications; this new probe, used in conjunction with the nanogold probe, will make it possible to obtain quantitative, high-resolution information about the location of proteins using X-ray microscopy. 相似文献
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16.
《Journal of Coordination Chemistry》2012,65(8):1384-1395
The new heteroleptic ruthenium(II) complex containing a 1H-pyridin-(2E)-ylidene (PYE) ligand was synthesized and characterized using UV/Vis, FTIR, and NMR spectroscopies, mass spectrometry, elemental analysis, and cyclic voltammetry. The photovoltaic performance of the ruthenium complex as a charge transfer photosensitizer in nc-titanium dioxide based dye-sensitized solar cell was studied and compared with cis-bis(isothiocyanato)(2,2′-bipyridyl-4,4′-dicarboxylato)(2,2′-bipyridyl-4,4′-di-nonyl)ruthenium(II) (Z907) under standard AM 1.5 sunlight. The complex CS90 gave a photocurrent density of 1.80?mA?cm?2, 400?mV open-circuit potential, and 0.58 fill factor yielding an efficiency of 0.42% where the reference Z907 yielded an efficiency of 4.12%. The decrease in conversion efficiency observed for CS90 is attributed to a steric interaction between PYE and the TiO2 surface that prevents optimum binding and also restricts ligand dynamics that are associated with oxidation state changes. 相似文献
17.
Zanarini S Vankova S Hernandez S Ijeri VS Armandi M Garrone E Bonelli B Onida B Spinelli P 《Chemical communications (Cambridge, England)》2012,48(46):5754-5756
We report the first use of cobalt aluminophosphate (CoAPO5) as a water oxidation catalyst. A decrease in the overvoltage by about 0.2 V with respect to catalyst free FTO has been observed. Additionally, we show that CoAPO5, deposited on ITO or Pt, can also act as a photo-electro-catalyst, as it generates enhanced oxidation currents in the presence of light starting from a bias of +0.8 V vs. Ag/AgCl. 相似文献
18.
Serpa C Schabauer J Piedade AP Monteiro CJ Pereira MM Douglas P Burrows HD Arnaut LG 《Journal of the American Chemical Society》2008,130(28):8876-8877
Time-resolved photoacoustic calorimetry is used to measure the energy released upon injection of an electron from an electronically excited dye adsorbed to nanocrystalline TiO2 into the conduction band of this material. More energy is released when the environment of the dye is made less polar, because the energy of the dye-oxidized state has a more pronounced solvent dependence than the edge of the conduction band of the TiO2 semiconductor. Such energy dependences should be considered in the design of more efficient dye-sensitized solar cells. 相似文献
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20.
TiO(2) sensitized by derivatized ruthenium bipyridyl complexes has been intensively investigated as a tool to utilize visible light. This article describes an alternative approach to attaching ruthenium complex sensitizers at the TiO(2)/H(2)O interface, which is a much simpler and more efficient way to produce hydrogen. The surface of TiO(2) particles are simply coated with perfluorosulfonate polymer (cation-exchange resin: Nafion), and then Ru(bpy)(3)(2+) (as a cationic form), whose bipyridyl ligands are not functionalized with carboxylic acid groups, are bound within the Nafion layer through electrostatic attraction. The visible-light-induced production of H(2) on Nf/TiO(2) using simple Ru(bpy)(3)(2+) as a sensitizer is far more efficient than that on Ru(dcbpy)(3)-TiO(2), upon which many sensitized photoelectrochemical conversion systems are based. Effects of various experimental parameters such as pH, concentration of Ru(bpy)(3)(2+), Nafion loading, and the kind of TiO(2) were investigated. Under optimized conditions, the H(2) production rate was about 80 mumol/h, which corresponds to an apparent photonic efficiency of 2.6%. The roles of the Nafion layer on TiO(2) in the sensitized H(2) production are proposed to be twofold: to provide binding sites for cationic sensitizers and to enhance the local activity of protons in the surface region. 相似文献