Кафедра биофизики

  • Increase font size
  • Default font size
  • Decrease font size
Главная страница Новости науки Journal of Photochemistry and Photobiology C: Photochemistry Reviews
Новости науки
ScienceDirect Publication: Journal of Photochemistry and Photobiology C: Photochemistry Reviews
ScienceDirect RSS

ScienceDirect Publication: Journal of Photochemistry and Photobiology C: Photochemistry Reviews
  • Non-equilibrium effects in ultrafast photoinduced charge transfer kinetics
    Publication date: December 2016
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 29

    Author(s): Serguei V. Feskov, Valentina A. Mikhailova, Anatoly I. Ivanov

    Modern laser-based spectroscopy has provided methods for detection ultrafast photochemical transformations occurring on the timescale of intramolecular and solvent reorganization. Such processes usually proceed in non-equilibrium regime, in parallel with nuclear relaxation, and often manifest strong deviations from the Kasha–Vavilov rule. In particular, they offer a possibility to control the yield of photoinduced electron transfer (ET) by using different excitation wavelengths. In the last decade the non-equilibrium charge transfer (CT) processes have attracted considerable interest from the scientific community due to their determining role in photosynthesis, dye-sensitized solar cells and various molecular electronic devices. Non-equilibrium of nuclear (intramolecular and solvent) degrees of freedom can be created by a pump pulse or by photoreaction itself at some of its stages. In this review both situations are considered and illustrated by examples in which non-equilibrium effects are pronounced. It is shown that ultrafast charge recombination in photoexcited donor–acceptor complexes and photochemical processes in donor–acceptor1–acceptor2 molecular compounds proceed predominantly in non-equilibrium (hot) regime. It is important that kinetics and product yields of these reactions demonstrate regularities that considerably differ from that observed in thermal reactions. Among them, the lack of the Marcus normal region in the free energy gap law for charge recombination of the excited donor–acceptor complexes, extremely low quantum yields of the thermalized charge separated states in ultrafast CT from the second excited state of the donor are most known. Although there have been many efforts to clarify microscopic mechanisms of non-equilibrium photoreactions by using ultrafast time-resolved spectroscopy techniques, control of the rate and efficiency of photoinduced charge transfer reactions is still an open challenge. One of the most important applications here is a suppression of ultrafast charge recombination in CT systems, formed either by direct optical excitation or by the preceding ET step. In these systems charge recombination is often regarded as undesirable process, leading to the loss of energy and selectivity of photoreaction. In this review some strategies of ultrafast charge recombination suppression are discussed. The non-equilibrium effects are interpreted from a unified point of view in context of the multichannel point-transition stochastic model. This approach demonstrates similarities and differences in ET mechanisms in various donor–acceptor molecular systems and allows formulating general regularities inherent to these phenomena. We believe that new advances in this research area will not only help to discover new fundamental information about these regularities, but will also have impact on many emerging technologies where ultrafast CT plays the central role.

    Graphical abstract

    image

    Highlights








  • Surface plasmon-driven photocatalysis in ambient, aqueous and high-vacuum monitored by SERS and TERS
    Publication date: June 2016
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 27

    Author(s): Zhenglong Zhang, Ping Xu, Xianzhong Yang, Wenjie Liang, Mengtao Sun









  • Prospects of electrochemically synthesized hematite photoanodes for photoelectrochemical water splitting: A review
    Publication date: December 2017
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 33

    Author(s): Yi Wen Phuan, Wee-Jun Ong, Meng Nan Chong, Joey D. Ocon

    Hematite (α-Fe2O3) is found to be one of the most promising photoanode materials used for the application in photoelectrochemical (PEC) water splitting due to its narrow band gap energy of 2.1eV, which is capable to harness approximately 40% of the incident solar light. This paper reviews the state-of-the-art progress of the electrochemically synthesized pristine hematite photoanodes for PEC water splitting. The fundamental principles and mechanisms of anodic electrodeposition, metal anodization, cathodic electrodeposition and potential cycling/pulsed electrodeposition are elucidated in detail. Besides, the influence of electrodeposition and annealing treatment conditions are systematically reviewed; for examples, electrolyte precursor composition, temperature and pH, electrode substrate, applied potential, deposition time as well as annealing temperature, duration and atmosphere. Furthermore, the surface and interfacial modifications of hematite-based nanostructured photoanodes, including elemental doping, surface treatment and heterojunctions are elaborated and appraised. This review paper is concluded with a summary and some future prospects on the challenges and research direction in this cutting-edge research hotspot. It is anticipated that the present review can act as a guiding blueprint and providing design principles to the scientists and engineers on the advancement of hematite photoanodes in PEC water splitting to resolve the current energy- and environmental-related concerns.

    Graphical abstract

    image






  • Enhancement of catalytic activity and oxidative ability for graphitic carbon nitride
    Publication date: September 2016
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 28

    Author(s): Wenjun Jiang, Wenjiao Luo, Jun Wang, Mo Zhang, Yongfa Zhu

    Growing awareness of energy conservation and pollutant elimination has been raised on graphitic carbon nitride (g-C3N4) recently thanks to the tunable electronic structure and excellent physicochemical stability of g-C3N4. This review summarizes the recent progress of g-C3N4 based materials regarding the catalytic activity improvement and oxidative ability enhancement. The former includes nanostructure design at different dimensions and fabrication of hybridized structure, core-shell structure or 3D hydrogel structure. The latter includes valence band modulation via conjugative effects of π-bond, copolymerization or doping, fabrication of Z-scheme heterojunction structure and synergetic effect of photoelectrocatalysis. The electronic structure and potential applications of g-C3N4 are also briefly discussed. This review provides new insights into the improvement of catalytic activity and oxidative ability for g-C3N4 materials and may help to facilitate their potential utilization in the field of energy transformation and environmental recovery.

    Graphical abstract

    image






  • The Paternò-Büchi reaction—Mechanisms and application to organic synthesis
    Publication date: December 2017
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 33

    Author(s): Maxime Fréneau, Norbert Hoffmann

    The [2+2] photocycloaddition between an electronically excited carbonyl compound and an alkene leading to oxetanes (Paternò-Büchi reaction) is one of the most investigated organic photochemical reaction. Regio-, stereo- and site selectivities are discussed as a consequence of the reaction mechanism. Spin multiplicity and electron transfer have a significant impact on the outcome of the reaction. Typical carbonyl and alkene reaction partners are presented indicating scope and limitation of the reaction. The Paternò-Büchi reaction possesses particular interest for being applied to organic synthesis, considering the difficulty for non-photochemical reactions to obtain oxetanes, with or without stereoselectivity. Mechanistic details are particularly focused. It has been applied as key step in various multi-step syntheses.

    Graphical abstract

    image






  • Oxygen imaging of living cells and tissues using luminescent molecular probes
    Publication date: March 2017
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 30

    Author(s): Toshitada Yoshihara, Yosuke Hirakawa, Masahiro Hosaka, Masaomi Nangaku, Seiji Tobita

    Oxygen imaging of biological cells and tissues is becoming increasingly important in cell biology and in the pathophysiology of various hypoxia-related diseases. The optical oxygen-sensing method using luminescent probes provides very useful, high spatial resolution information regarding oxygen distribution in living cells and tissues. This review focuses on recent advances in biological oxygen measurements based on the phosphorescence quenching of probe molecules by oxygen, and on hypoxia-sensitive fluorescent probes. Special attention is devoted to metal complex probes, Pt(II)- and Pd(II)-porphyrins, Ru(II) complexes, and Ir(III) complexes. Current knowledge regarding the mechanism of phosphorescence quenching of metal complexes by oxygen is described in relation to the oxygen sensitivity of the probes, and recent advances in optical oxygen probes and detection techniques for intracellular and tissue oxygen measurements are reviewed, emphasizing the usefulness of chemical modifications for improving probe properties. Tissue oxygen imaging and hypoxic tumor imaging using these metal complex probes demonstrate the vast potential of optical oxygen-sensing methods using luminescent probes.







  • Lanthanide complex-derived white-light emitting solids: a survey on design strategies
    Publication date: Available online 11 November 2017
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews

    Author(s): Sunil SeethaLekshmi, A.R. Remya, M.L.P. Reddy, Sunil Varughese

    Solid-state materials with tunable light emission characteristics offer an attractive prospect. Unique luminescence features of trivalent lanthanide (LnIII) ions—sharp characteristic emission in the visible and near-infrared (NIR) spectral regions, exceptional color purity, long luminescence lifetimes, high quantum yield and large Stokes shifts—afford them as promising white-light source materials. The review provides an overview of the recent developments in the Ln- complex-based solid-state white-light emitters with particular emphasis on different design strategies and photoluminescence features to augment the foundations of factual knowledge further. The approaches adopted in the lanthanide coordination complexes—logical codoping of LnIII in various compositions, lanthanide encapsulation in MOF pores, infinite coordination particles, and lanthanide incorporated composites—to attain tunable white-light emission, will be discussed. The pros and cons of different adopted strategies in term of further processing of the materials into real-world applications as well as the imminent challenges are also reviewed and put in prospect.

    Graphical abstract

    image






  • In situ patterning and controlling living cells by utilizing femtosecond laser
    Publication date: September 2016
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 28

    Author(s): Kazunori Okano, Hsin-Yun Hsu, Yaw-Kuen Li, Hiroshi Masuhara

    Photo-induced processes have high potential in in situ patterning and controlling living cells, whose developments are introduced and recent progresses by utilizing femtosecond laser are described. Photochemical and photothermal surface modification performed by conventional light and nanosecond laser irradiation is summarized and their applicability is considered. Femtosecond laser ablation has superior features due to its photomechanical mechanism, which is confirmed by ultrafast spectroscopy and imaging of a model film under laser ablation. Femtosecond laser ablation of physiological solutions generates shockwave and cavitation bubbles, which is employed for patterning and manipulating living cells. Femtosecond laser ablation fabricating cytophobic and cytophilic domains enable us to form living cell patterns and to study cell migration and cell–cell interaction. Finally summary and perspective are presented.

    Graphical abstract

    image






  • Interfacial charge transfer in semiconductor-molecular photocatalyst systems for proton reduction
    Publication date: Available online 3 November 2017
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews

    Author(s): Xiuli Wang, Can Li

    Solar fuels have proven to be one of the important promising approaches to provide clean energy of H2. It is an effective strategy for H2 production to construct photocatalytic systems using semiconductor as a sensitizer and molecular catalyst as the H2 evolution catalyst. In the semiconductor-molecular photocatalyst systems (SMP systems) for proton reduction, the interfacial charge transfer, including electron and hole transfer, is the determining factor for the photocatalytic process from kinetic aspects. The knowledge of the interfacial charge transfer is of utmost importance for understanding the photocatalytic systems. This review focuses on the interfacial charge transfer in SMP systems for proton reduction, with a special emphasis on the advances in the studies on the kinetic aspects of interfacial charge transfer.







  • Nitrogen-doped titanium dioxide: An overview of material design and dimensionality effect over modern applications
    Publication date: June 2016
    Source:Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 27

    Author(s): Shahzad Abu Bakar, Caue Ribeiro

    TiO2 material has gained attention as the most studied semiconductor material for photocatalytic purposes, including their use in devices for clean energy production, such as solar cells and water splitting systems. However, the wide band gap of this material limits applications to UV light, which also confines the use of solar irradiation as the energy source. Much research in the last years is showing the ability of N doping into TiO2 to promote light absorption in the visible range but, to date, it is still controversy if this doping is beneficial to the photocatalytic process, as well as the synthetic methods are not well stabilized yet. Then, this paper summarizes the recent advancement in the structural design perspective of N-doped TiO2 photocatalyst, in a critical analysis of its application for environmental purposes. We reported the dimensionality effect associated with modified N-doped TiO2 structure for its characteristics properties and photocatalytic performance; counting more specifically its charge transportation, surface area, adhesion, reflection and absorption properties. A concise view of the doping effect over morphology in 0, 1, 2 and 3-dimensional ranges was provided, in order to understand which effects are also occurring on the materials besides the photocatalytic response. Furthermore, selected recent and significant advances in the area of renewable energy applications for modified N-doped TiO2 were assessed with the particular importance given towards the electricity generation by dye-sensitized solar cells and lithium-ion batteries rechargeable for electric energy storage.

    Graphical abstract

    image






Научная работа