Journal of Photochemistry and Photobiology C: Photochemistry Reviews最新文献

Photocatalytic reduction of CO₂ is one important approach to alleviate greenhouse gas emission and energy crisis, which has gained huge attention in the past decades. However, the lack of understanding complex reaction mechanism impedes new catalysts design. It is also very difficult to understand the mechanism by using only experimental approaches. For this concern, theoretical calculations can effectively supplement the experimental deficiency and thus play an important role. Recently theoretical calculations have been performed on adsorption, migration and reduction of CO₂ molecule on the photocatalyst surface, leading to useful information that have contributed greatly to this field. This review summarizes recent advances in first-principles calculations about CO₂ photoreduction over various semiconductor photocatalysts like metal oxides, sulfides and g-C₃N₄. The methods, models, adsorption and reaction pathways have been discussed in detail. The perspective about future investigation on the photocatalytic reduction of CO₂ using first principles calculations is also presented.

Helical light fields may carry both orbital angular and spin angular momentum which is respectively associated with their helical wavefronts (optical vortices) and rotating transverse electric fields. Interestingly, these helical light fields interact with materials and the orbital angular momentum of these fields can physically twist a range of materials, including metals, semiconductors, polymers, and liquids. With the aid of spin angular momentum, these fields can also form a range of helical structures. This light-matter interaction based on transfer of angular momentum has the potential to revolutionize industrial processes and enable technologies, such as advanced non-contact and nozzle-free printing. In this review paper, we focus on this printing technique, a process which we herein refer to as optical vortex laser induced forward transfer, and we show how it can be used for the production of next generation printed photonics/electronics/spintronics devices. Herein we review the interactions between the angular momentum of light and materials, and we discuss the ways in which optical vortices can be used to produce a variety of exotic structures. We also discuss the current state-of-the art of laser-induced forward-transfer technologies and detail some of the most novel devices, which have been fabricated using this optical vortex laser induced forward transfer, including hexagonal close-packed photonic-rings and plasmonic nanocores.

The distinct features of chlorophylls in photosynthesis have led to the formation of numerous derivatives for applications encompassing solar energy conversion, molecular photonics, photodynamic therapy, and molecular imaging. Synthetic chlorins created de novo and bearing a geminal dimethyl group in the reduced ring have proved invaluable for fundamental studies. Four decades of research have led to accumulation of tabulated spectra for > 400 such synthetic chlorins with distinct structural frameworks (17-oxochlorins, 13¹-oxophorbines, chlorinimides) and substituents (alkyl, aryl, ethynyl, phenylethynyl, acetyl, formyl) located at specific (meso, β) positions. In this review, spectral traces (324 absorption, 247 fluorescence) are assembled along with photophysical data including the molar absorption coefficient (ε), fluorescence quantum yield (Φ_f) and singlet excited-state lifetime (τ_s). The review uses the accumulated spectral data derived from chlorins all containing a uniform molecular scaffold to (1) highlight the effects of molecular structure on spectral features, and (2) identify trends including how ε, Φ_f and τ_s vary with wavelength and other features. Use of a common geminal-dimethyl-substituted chlorin scaffold – beginning with no substituents, to one substituent at designated sites, and to 2 or more substituents – provides a systematic Aufbau approach for understanding the absorption spectra of chlorins on a path to and beyond the native chlorophylls. The review provides insights concerning the rational design of potent analogues of Nature’s preeminent red-region absorbers for potential utilization in diverse applications and is aimed at multiple audiences: those interested in spectral properties, tetrapyrrole photophysics, and the molecular design of new chromophores.

Bioluminescence (BL) is an amazing natural phenomenon whose visible light is produced by living organisms. BL phenomenon is quite pervasive and has been observed in 17 phyla of 4 kingdoms. This fascinating natural phenomenon has unceasingly attracted people’s curiosity from ancient era to today. For a very long time, we can only receive some sporadic and static information from experimental observations, the mechanism of most BL remains is unclear. How the chemical reaction of BL process is initiated? Where the energy for light emission comes from? How does the light emitter produce? What is the light emitter for a wild bioluminescent organism? How to regain luciferin for next bioluminescence when it is used up? The luciferin is utilized forthwith or stored and release for subsequent light emission? What factors affect the color and strength of a bioluminescence? How to artificially tune the bioluminescence for special application? Computational BL plays unreplaceable role in answering these mechanistic questions. In contrast with experimental BL, computational BL came very late. In the past two decades, computational BL has touched nearly all the bioluminescent systems with chemical bases via the method of multiscale simulation. In this review, the author firstly introduced the history, types and general chemical process of BL. Then, the computational scheme on BL was briefly epitomized. Using firefly BL as a paradigmatic case, the author summarized theoretical investigation on the six stages of general chemical process in a BL cycle: luciferin oxidation, peroxide thermolysis, light emission, luciferin regeneration, luciferin storage and luciferin release. At each stage, the available theoretical studies of other bioluminescent organisms are briefly introduced and compared with the firefly system. Basing on the mechanistic understanding, the author reviewed the up-to-date theoretical design on bioluminescent systems. Again, the firefly was mainly focused on, and the other possible systems were just briefly introduced. This review summarized the theoretical studies to date on BL and addressed the status, critical challenges and future prospects of computational BL.

In this mini-review, recent advances on the role of a focused laser in micro- and nanofluidic systems is widely introduced with special interest in thermo-fluid dynamical aspects and their importance in optical manipulation. As a brief introduction to microfluidic systems, we describe the advantages and challenges of the use of micro- and nanoscale confinement in optical trapping, as well as standard fabrication techniques for micro- and nanofluidic systems. From thermo-fluid dynamical viewpoints, various phenomena that accompany a laser irradiation to fluidic devices, are explained in detail. These phenomena can affect the optical trapping of target materials significantly, and are classified into two categories: one that induces the fluid flow around the target and another that directly acts on it as an external force. These classes are reviewed by shedding light on some recent cutting-edge researches for optical manipulation. Some applications using thermo-fluid dynamics in microfluidic systems for the measurement of optical forces and for the separation, measurement, and detection of target materials are also introduced.

In this review, we introduce the operating principle of photoinduced force microscopy (PiFM) and its applications. First, we introduce that the photoinduced force includes the gradient force and the scattering force. Next, we explain how to eliminate the effects of photothermal effects on the metal tip and sample surface caused by light irradiation. Then, we introduce a PiFM operating in air based on the tapping mode and present images of SiNc clusters. Furthermore, we introduce a PiFM operating in vacuum based on the frequency modulation (FM) mode, and present the results of three-dimensional photo-induced force vector measurements of semiconductor quantum dots.

Chiral light-matter interaction occurs when the system consists of the matter and the light has a chiral structure, which is generically called the chiro-optical effect. Circular dichroism and optical rotation are representative spectroscopic methods based on chiro-optical effects. Chiro-optical effects have been widely utilized to detect chiral materials in the system. The chiro-optical effect also has the potential to create chiral materials from achiral materials and chiral optical fields, and to generate chiral optical fields from chiral matter systems. To achieve that, the design and observation of chiral optical field structures are essential. In this article, we describe local chiral optical fields generated in the peripheries of nanomaterials (typically metal nanostructures) irradiated with light. We summarize basic characteristics of nanoscale local chiral optical fields, methods to observe/control the chiral optical field structures at nanomaterials. Then some chemical, optical, and mechanical effects of designed chiral optical fields are described. Chiral nanostructures were created from achiral nanomaterials combined with circularly polarized light. Nucleation of chiral crystals of achiral molecules was achieved by circularly polarized light with the aid of plasmonic materials. Circularly polarized luminescence was observed from achiral fluorescent molecules conjugated with chiral plasmonic nanostructures. On mechanical characteristics, optical forces exerted on chiral materials were found to be dependent on the handedness of incident circularly polarized light, which can be utilized to discriminate the chirality of the material. The concept can be further generalized to the spin-dependent asymmetric light-matter interactions, which will create not only the molecular- and nano-scale chiral structures but also various novel functions of materials that are correlated with the handedness degree of freedom.

Recently, laser-induced nucleation (LIN) has been attracting significant attention because of its many advantages, including non-mechanical contact, spatiotemporal controllability, and high nucleation probability. Consequently, there is a high demand for precise control methods for polymorphism, particularly in the pharmaceutical industry. The precise control of nucleation and polymorphism, as well as the expansion of their versatility, is indispensable in elucidating the mechanism of nucleation and polymorphism. If LIN can be exploited to precisely control polymorphism, it will be possible to appropriately control the solubility, bioavailability, and stability of targets. Currently, numerous mechanisms for LIN involving targets, solvents, laser light sources, and additives have been proposed. In this review, the authors summarize the history and current state of the research on nucleation and LIN-controlled polymorphism reported over the past two decades while focusing on the different light sources (pulsed laser vs. continuous-wave laser). Furthermore, the authors introduce the classical nucleation and two-step nucleation models and discuss the similarities and differences in the mechanisms of nucleation and polymorphism control based on these two models.

Two-dimensional (2D) materials have become a worldwide hot topic due to their fascinating properties, including high carrier mobility, tunable bandgap, ultra-broadband optical absorption and response. The versatility of 2D materials enable it hold great potential to achieve high performance Terahertz (THz) optoelectronic devices. However, the THz radiation, range from infrared to microwave, known as the THz gap, much less investigated than that of other electromagnetic wave. Motivated by this lack of knowledge, we reviewed the recent advances of research into 2D materials based THz optoelectronic devices. Firstly, we introduced the background and motivation of this review. Then, the suitable 2D material candidates are exhibited, followed by a comprehensive review of their applications in THz generation devices, modulator, THz shielding, and photodetectors. Finally, the challenges and further development directions are concluded. We believe that some milestone investigations of 2D materials based THz optoelectronic devices will emerge soon, which will bring about great industrial revelations in 2D materials-based nanodevice commercialization.