13558-31-1Relevant academic research and scientific papers
Photocatalysis through Excitation of Adsorbates. 3. Effect of Electron Acceptors on the Efficiency of Interfacial Charge Separation
Takizawa, Takuo,Watanabe, Tadashi,Honda, Kenichi
, p. 51 - 55 (1980)
Charge separation in photoexcited rhodamine B-CdS-electron acceptor systems was investigated photochemically and photoelectrochemically, by using acceptors with different standard reduction potentials (E0red.).The formal quantum efficiency (FQE) of N-deethylation of the dye after photoinduced electron injection into CdS (in photochemical suspension systems) and sensitized photocurrents flowing through a single-crystal CdS membrane separating the dye from an acceptor (in photoelectrochemical systems) were measured as a function of concentration of acceptors.Both FQE and sensitized photocurrents reflect the efficiency of charge separation between the dye and acceptors.Results indicate that charge separation occurs only in the presence of CdS and its efficiency rises as E0red. of the acceptor is more positive.The effectiveness of the present systems for photoinduced charge separation is discussed.
A comparative study on the efficacy of different probes to predict the photo-activity of nano-titanium dioxide toward biomolecules
Marucco,Carella,Fenoglio
, p. 89559 - 89568 (2015)
TiO2 is a reactive material able to cause the degradation of organic molecules following activation by UV light. This reactivity may be useful, e.g. in environmental or medical applications, but undesired when TiO2 is used as a UV filter in cosmetics and composites since it reduces the photo-stability of the material, and represents a possible pathway of injury. Conventional methods to measure the photo-activity of TiO2 include the degradation of small molecules or dyes. However the suitability of these methods to predict the photo-activity of TiO2 in biological systems is uncertain. This is the first product of a study, conducted within the FP7 EU project SETNanoMetro, that has as a main goal the standardizations of protocols to assess the oxidative potential of TiO2 nanopowders in biofluids. Here, the ability of a series of nano-TiO2 powders exhibiting different crystalline phases to degrade rhodamine B, a dye commonly used in photo-catalysis, and two model biomolecules (linoleic acid and 2-deoxyribose) under simulated sunlight was compared. Electron paramagnetic resonance (EPR) spectroscopy associated to different spin-probes or spin-traps was used to elucidate the reactive species involved in the processes. The results show how the photo-efficiency of TiO2 is affected by the kind of probe and by the presence of species that adsorb at the surface of the nanoparticles underlining the need of appropriate standard operating procedures (SOP) to evaluate the oxidative damage potential of semiconducting nanomaterials.
The upconversion and enhanced visible light photocatalytic activity of Er3+-doped tetragonal BiVO4
Yang, Wei,Tan, Guoqiang,Ren, Huijun,Zhang, Lili,Zhao, Chengcheng,Xia, Ao
, p. 7324 - 7329 (2015)
Er3+-doped BiVO4 with tetragonal structure is prepared by the microwave hydrothermal method. X-ray diffraction and Rietveld refinement demonstrate that the structure is transformed from the monoclinic (C2/c:c3) phase to the tetragonal (I41/amd:2) phase by doping with Er3+ ions. Er3+ doping also influences the morphology change of BiVO4 from irregular flake-like crystal to rod-like crystal, which leads to the increase of the surface areas from 3.25 to 11.96 m2 g-1. Compared with the monoclinic BiVO4, the upconversion of the Er3+-doped tetragonal BiVO4 occurs through the transitions from the 4I15/2 ground state to 4F7/2, 2H11/2, and 4F9/2 states, respectively. The photocatalytic experiment indicates that the tetragonal BiVO4 (8 at.%) with a larger specific surface area (9.88 m2 g-1) shows the best photocatalytic activity under visible light irradiation, which can efficiently improve the degradation rate of RhB up to 97.2% at 150 min. This journal is
Hierarchical BiOI nanostructures supported on a metal organic framework as efficient photocatalysts for degradation of organic pollutants in water
Jahurul Islam,Kim, Hyun Kook,Amaranatha Reddy,Kim, Yujin,Ma, Rory,Baek, Heehyun,Kim, Joonghan,Kim, Tae Kyu
, p. 6013 - 6023 (2017)
Semiconductor-based photocatalysis is a green method for the removal of toxic organic pollutants by decomposition into harmless products. However, traditional single-component semiconductors are unable to reach high degradation efficiencies due to excessive photo charge carrier recombination. The use of hybrid nanocomposite photocatalysts is a promising strategy for overcoming this problem by reducing recombination as well as ensuring that large amounts of solar energy are harvested. Herein, a novel visible-light-active hybrid nanocomposite, BiOI/MIL-88B(Fe), was successfully synthesized through a simple precipitation method. In the BiOI/MIL-88B(Fe) composite, both BiOI and MIL-88B(Fe) have improved charge carrier separation and reduced recombination via a simple Z-scheme mechanism. Photocatalytic degradation of the pollutant RhB was carried out during irradiation of the as-synthesized composites with simulated solar light, and the BiOI/MIL-88B(Fe) (2 wt%) composite was found to exhibit the highest photocatalytic activity among the composites. In addition, colorless phenol and ciprofloxacin (CIP) degradation experiments were also performed to confirm the visible light photocatalytic performance of the BiOI/MIL-88B(Fe) hybrid nanocomposite. Scavenger experiments, PL analysis, NBT transformations, and TA-PL experiments all supported the proposed Z-scheme mechanism of the BiOI/MIL-88B(Fe) composite photocatalyst. Moreover, simple separation from solution provides this 3D composite with good reusability and long-term stability.
Visible light photodegradation of rhodamine B over VDF/CTFE copolymer-templated crystalline mesoporous titania
Zi, Guoli,Wang, Yi,Zheng, Kai,Zhao, Huan,Wang, Fuzhi,Zhang, Wenjun,Yan, Zhiying,He, Jiao,Wang, Jiaqiang
, p. 2383 - 2391 (2012)
Mesoporous TiO2 with anatase crystalline structure (MTiO 2/F2319) has been synthesized by using vinylidene fluoride/chlorotrifluoroethylene copolymer (1:9 in mole, F2319) as template. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and N2 adsorption/desorption. It was found that without any external doping, MTiO2/F2319 exhibited significantly higher photocatalytic activities for the degradation of rhodamine B (RhB) dye than P25 TiO2 under visible light irradiation. Furthermore, the UV-Vis absorption maximum of the dye solution exhibited a gradual hypsochromic shift due to de-ethylation and degradation of RhB dye. Springer Science+Business Media B.V. 2012.
Self assembled flower like CdS-ZnO nanocomposite and its photo catalytic activity
Jana,Pal,Chatterjee
, p. 510 - 515 (2014)
Self assembled flower like CdS-ZnO nanocomposite has been synthesized by a facile chemical route and the prepared materials have been investigated as catalyst in the photodegradation of rhodamine B (RhB) in aqueous solution facilitated by the effective charge transfer mechanism in this coupled semiconductor system. CdS has been grown first and then petal-like ZnO has been produced to assemble into a flower like nanostructure. XRD, SEM, TEM, EDX have been employed to study the structural, morphological and compositional details of this unique nanostructure. It is observed that a strong quenching of band-edge emission of CdS following the growth of ZnO petal on it which is evidence for the occurrence of charge transfer between CdS and ZnO. The strong photocatalytic activity of this novel nanostructure on RhB has been investigated in details.
New latent fluorophore for DT diaphorase
Huang, Sheng-Tung,Lin, Yuh-Ling
, p. 265 - 268 (2006)
This study describes the design and synthesis of a novel latent fluorophore 3 for DT diaphorase based on the trimethyl lock effect and characterization of its enzymatic kinetics. Fluorophore 3 is also a sensitive fluorimetric reagent for detecting glucose when coupled with DTD and glucose dehydrogenase.
Fluorescence-Lifetime-Sensitive Probes for Monitoring ATP Cleavage
Hammler, Daniel,Marx, Andreas,Zumbusch, Andreas
, p. 15329 - 15335 (2018)
Adenosine triphosphate (ATP) probes modified with fluorescence dyes that change their fluorescence properties upon cleavage are an interesting tool for monitoring enzymatic ATP turnover. As a readout parameter, fluorescence lifetime is attractive because it is nearly independent of concentration. In our study, we synthesised and investigated fifteen different ATP analogues, in which the fluorophores were attached to the γ-phosphate of ATP. All analogues showed distinctly different fluorescence lifetimes compared to the corresponding values of the free fluorophores. Both increases and decreases in fluorescence lifetime were observed upon attachment to ATP. To shed light on the photophysical processes governing the lifetime changes, we performed photoelectron spectroscopy in air (PESA) to determine HOMO energy levels and time-resolved fluorescence spectroscopy to obtain rate constants. We present evidence that fluorescence quenching in the compounds tested is dynamic and attributed to photoinduced electron transfer (PET), whereas fluorescence lifetime increases are caused by stacking interactions between chromophore and the nucleobase reducing non-radiative relaxation. Finally, we demonstrate that enzymatic cleavage of the ATP analogues presented can be followed by continuous monitoring of fluorescence lifetime changes.
A novel synthetic route for magnetically retrievable Bi2WO 6 hierarchical microspheres with enhanced visible photocatalytic performance
Liu, Zhi,Chen, Feitai,Gao, Yuanpeng,Liu, Yang,Fang, Pengfei,Wang, Shaojie
, p. 7027 - 7030 (2013)
We report a reliable and effective strategy to synthesize magnetically recyclable Bi2WO6 microspheres using Fe3O 4 nanoparticles as supports. The as-prepared hierarchical photocatalyst displays excellent photocatalytic activity and reusability under visible light irradiation. The Royal Society of Chemistry 2013.
Photocatalytic application of nanosized CdS immobilized onto functionalized MWCNTs
Chronopoulos,Karousis,Zhao,Wang,Shinohara,Tagmatarchis
, p. 7429 - 7434 (2014)
Nanosized semiconductor CdS immobilized onto modified multi-walled carbon nanotubes (MWCNTs) carrying poly(amidoamine) dendron units were visualized by HR-TEM. Evidently, spherical CdS nanoparticles 3-5 nm in diameter were identified. Moreover, EDX spectr
