超薄Ni掺杂ZnIn2S4纳米片用于光催化醇裂解同时制备C-C耦合产物及氢气

光催化析氢技术被认为是解决化石能源紧缺和环境污染问题的有效途径之一.在传统的光解水体系中,析氧半反应因涉及到复杂的四电子转移和O=O双键形成,成为光催化水分解的决速步骤.光生空穴牺牲试剂的引入虽然可以在一定程度上提高体系的光催化效率,但同时造成了光生空穴氧化能力的浪费,且增加了系统成本.相比之下,构建由光催化析氢和选择...     

Emerging materials for plasmon-assisted photoelectrochemical water splitting

Energy production and environmental pollution are the two major problems the world is facing today. The depletion of fossil fuels and the emission of harmful gases into the atmosphere leads to the research on clean and renewable energy sources. In this context, hydrogen is considered an ideal fuel to meet global energy needs. Presently, hydrogen is produced from fossil fuels. However, the most desirable way is from clean and renewable energy sources, like water and sunlight. Sunlight is an abundant energy source for energy harvesting and utilization. Recent studies reveal that photoelectrochemical (PEC) water splitting has promise for solar to hydrogen (STH) conversion over the widely tested photocatalytic approach since hydrogen and oxygen gases can be quantified easily in PEC. For designing light-absorbing materials, semiconductors are the primary choice that undergoes excitation upon solar light irradiation to produce excitons (electron-hole pairs) to drive the electrolysis. Visible light active semiconductors are attractive to achieve high solar to chemical fuel conversion. However, pure semiconductor materials are far from practical applications because of charge carrier recombination, poor light-harvesting, and electrode degradation. Various heteronanostructures by the integration of metal plasmons overcome these issues. The incorporation of metal plasmons gained significance for improving the PEC water splitting performance. This review summarizes the possible main mechanisms such as plasmon-induced resonance energy transfer (PIRET), hot electron injection (HEI), and light scatting/trapping. It also deliberates the rational design of plasmonic structures for PEC water splitting. Furthermore, this review highlights the advantages of plasmonic metal-supported photoelectrodes for PEC water splitting.     

用于光催化能量转换的Z-型异质结的研究进展

Inspired by the photosynthesis of green plants, various artificial photosynthetic systems have been proposed to solve the energy shortage and environmental problems. Water photosplitting, carbon dioxide photoreduction, and nitrogen photofixation are the main systems that are used to produce solar fuels such as hydrogen, methane, or ammonia. Although conducting artificial photosynthesis using man-made semiconducting materials is an ideal and potential approach to obtain solar energy, constructing an efficient photosynthetic system capable of producing solar fuels at a scale and cost that can compete with fossil fuels remains challenging. Therefore, exploiting the efficient and low-cost photocatalysts is crucial for boosting the three main photocatalytic processes (light-harvesting, surface/interface catalytic reactions, and charge generation and separation) of artificial photosynthetic systems. Among the various photocatalysts developed, the Z-scheme heterojunction composite system can increase the light-harvesting ability and remarkably suppress charge carrier recombination; it can also promote surface/interface catalytic reactions by preserving the strong reductive/oxidative capacity of the photoexcited electrons/holes, and therefore, it has attracted considerable attention. The continuing progress of Z-scheme nanostructured heterojunctions, which convert solar energy into chemical energy through photocatalytic processes, has witnessed the importance of these heterojunctions in further improving the overall efficiency of photocatalytic reaction systems for producing solar fuels. This review summarizes the progress of Z-scheme heterojunctions as photocatalysts and the advantages of using the direct Z-scheme heterojunctions over the traditional type Ⅱ, all-solid-state Z-schemel, and liquid-phase Z-scheme ones. The basic principle and corresponding mechanism of the two-step excitation are illustrated. In particular, applications of various types of Z-scheme nanostructured materials (inorganic, organic, and inorganic-organic hybrid materials) in photocatalytic energy conversion and different controlling/engineering strategies (such as extending the spectral absorption region, promoting charge transfer/separation and surface chemical modification) for enhancing the photocatalytic efficiency in the last five years are highlighted. Additionally, characterization methods (such as sacrificial reagent experiment, metal loading, radical trapping testing, in situ X-ray photoelectron spectroscopy, photocatalytic reduction experiments, Kelvin probe force microscopy, surface photovoltage spectroscopy, transient absorption spectroscopy, and theoretical calculation) of the Z-scheme photocatalytic mechanism, and the assessment criteria and methods of the photocatalytic performance are discussed. Finally, the challenges associated with Z-scheme heterojunctions and the possible growing trend are presented. We believe that this review will provide a new understanding of the breakthrough direction of photocatalytic performance and provide guidance for designing and constructing novel Z-scheme photocatalysts.      

Molecular and Supramolecular Multiredox Systems

The design and synthesis of molecular and supramolecular multiredox systems have been summarized. These systems are of great importance as they can be employed in the next generation of materials for energy storage, energy transport, and solar fuel production. Nature provides guiding pathways and insights to judiciously incorporate and tune the various molecular and supramolecular design aspects that result in the formation of complex and efficient systems. In this review, we have classified molecular multiredox systems into organic and organic-inorganic hybrid systems. The organic multiredox systems are further classified into multielectron acceptors, multielectron donors and ambipolar molecules. Synthetic chemists have integrated different electron donating and electron withdrawing groups to realize these complex molecular systems. Further, we have reviewed supramolecular multiredox systems, redox-active host-guest recognition, including mechanically interlocked systems. Finally, the review provides a discussion on the diverse applications, e. g. in artificial photosynthesis, water splitting, dynamic random access memory, etc. that can be realized from these artificial molecular or supramolecular multiredox systems.     

Photoresponsive Carbon-Azobenzene Hybrids: A Promising Material for Energy Devices

Advancements in renewable energy technology have been a hot topic in the field of photoresponsive materials for a sustainable community. Organic compounds that function as photoswitches is being researched and developed for use in a variety of energy storage systems. Azobenzene photoswitches can be used to store and release solar energy in solar thermal fuels. This review draws out the significance of azobenzene as photoswitches and its recent advances in solar thermal fuels. The recent developments of nano carbon templated azobenzene, their interactions and the effect of substituents are highlighted. The review also introduces their applications in solar thermal fuels and concludes with the challenges and future scope of the material. The advancements of solar thermal fuels with cost effective and desired optimal properties can be explored by scientists and engineers from different technological backgrounds.     

Photocatalytic hydrogen production

The efficient storage of solar energy in chemical fuels, such as hydrogen, is essential for the large-scale utilisation of solar energy systems. Recent advances in the photocatalytic production of H(2) are highlighted. Two general approaches for the photocatalytic hydrogen generation by homogeneous catalysts are considered: HX (X = Cl, Br) splitting involving both proton reduction and halide oxidation via an inner-sphere mechanism with a single-component catalyst; and sensitized H(2) production, employing sacrificial electron donors to regenerate the active catalyst. Future directions and challenges in photocatalytic H(2) generation are enumerated.     

New trends in polyoxometalate photoredox chemistry: from photosensitisation to water oxidation catalysis

Molecular metal oxide clusters, so-called polyoxometalates (POM) have been extensively used as homogeneous photocatalysts in various photoredox reactions such as the oxidation of alkanes, alkenes and alcohols as well as the light-induced mineralisation of various organic and inorganic pollutants. The more general application of POMs as photoactive compounds, in particular in solar energy harnessing, has been hampered as the clusters typically absorb light in the UV-region only. Over the past decade, concepts have been put forward on how the reactivity of this class of compounds can be optimised to improve their overall photoactivity, and a particular focus has been on the design of photocatalytic processes which allow the conversion of solar light into useful chemical reactivity. This perspective gives a brief overview of general aspects of POM photochemistry and critically discusses the advantages and challenges of a range of POM-based systems for photooxidations and photoreductions with a focus on the development of sustainable solar light conversion systems.     

有机氧化还原液流电池的研究进展

氧化还原液流电池（简称液流电池）是一种正在积极研制开发的新型大容量电化学储能装置,其活性物质是流动的电解质溶液,最显著的特点是规模化蓄电. 在广泛利用可再生能源的呼声高涨形势下,可以预见液流电池将迎来一个快速发展的时期. 氧化还原活性物质是液流电池能源转化的载体,也是液流电池中最核心的部分.传统液流电池利用无机材料作为活性物质,然而,无机材料成本高、毒性、资源有限、形成枝晶和电化学活性低等缺点限制了液流电池的大规模应用. 有机活性物质由于具有成本低、“绿色”、资源丰富、分子能级易于调节和电化学反应快等优点,引起了国内外的广泛关注. 近年来,有机液流电池的性能得到快速提升,一系列有机活性物质相继被开发出来. 本文梳理了近年来有机液流电池的研究进展. 首先简要介绍了液流电池的应用领域和技术特点;然后根据电解液种类的不同,详细讨论了有机活性物质在水系和非水系液流电池的应用情况;最后展望了有机液流电池走向实际应用所面临的挑战和潜在研究方向.     

Emerging approach in semiconductor photocatalysis: Towards 3D architectures for efficient solar fuels generation in semi-artificial photosynthetic systems

Interest in the application of semiconductors toward the photocatalytic generation of solar fuels, including hydrogen from water-splitting and hydrocarbons from the reduction of carbon dioxide, remains strong due to concerns over the continued emission of greenhouse gases as well as other environmental impacts from the use of fossil fuels. While the efficiency and durability of such systems will depend heavily on the types of the semiconductors, co-catalysts, and mediators employed, the dimensionality of the semiconductors employed can also have a significant impact. Recognizing the broad nature of this field and the many recent advances in it, this review focuses on the emerging approaches from 0-dimensional (0D) to 3-dimensional (3D) semiconductor photocatalysts towards efficient solar fuels generation. We place particular emphasis on systems that are “semi-artificial”, that is, hybrid systems that integrate naturally occurring enzymes or whole cells with semiconductor components that harvest light energy. The semiconductors in these systems must have suitable interfacial properties for immobilization of enzymes to be effective photocatalysts. These requirements are particularly sensitive to surface structures and morphology, making the semiconductor dimensionality a critical factor. In addition to providing an overview of advances towards designing 3D architecture in semi-artificial photosynthetic field, we also present recent advances in fabrication strategies for 3D inorganic photocatalysts.     

从液态阳光人工光合成淀粉

人工光合成是利用太阳能等可再生能源通过连续催化反应将水和二氧化碳转化为液态燃料的过程,是减少二氧化碳排放、实现绿色低碳发展的一种重要方法.人工光合成的目标产物不仅包括二氧化碳转化与利用得到的能源小分子,还包括淀粉和蛋白质等生物基大分子.在自然光合作用中,高等植物、绿藻和蓝细菌首先利用太阳能将水氧化放出氧气并产生还原型辅...     

Photoredox processes in coordination compounds

Transition metal complexes display a number of charge-transfer bands in the absorption spectra. Optical excitation of the metal complexes produces a variety of products depending upon the nature of the excited state. Cobalt (III) ammine complexes on excitation in the CTTM bands produce cobalt(II) and oxidised ligand. Ruthenium(II) complexes on excitation in the cm. band leads to the oxidation of the metal centre. In certain reactions participation of the solvent in the primary photoredox reactions has also been reported. In recent years extensive investigations have been undertaken to utilize the photoredox systems of coordination compounds to convert solar energy to electricity or hydrogen.     

Recent advances in Cu-based nanocomposite photocatalysts for CO_2 conversion to solar fuels

CO_2 conversion via photocatalysis is a potential solution to address global warming and energy shortage.Photocatalysis can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of CO_2 to useful solar fuels such as CO, CH_4, CH_3OH, and C_2H_5OH. Among studied formulations, Cubased photocatalysts are the most attractive for CO_2 conversion because the Cu-based photocatalysts are low-cost and abundance comparing noble metal-based catalysts. In this literature review, a comprehensive summary of recent progress on Cu-based photocatalysts for CO_2 conversion, which includes metallic copper, copper alloy nanoparticles(NPs), copper oxides, and copper sulfides photocatalysts, can be found. This review also included a detailed discussion on the correlations of morphology, structure, and performance for each type of Cu-based catalysts. The reaction mechanisms and possible pathways for productions of various solar fuels were analyzed, which provide insight into the nature of potential active sites for the catalysts. Finally, the current challenges and perspective future research directions were outlined, holding promise to advance Cu-based photocatalysts for CO_2 conversion with much-enhanced energy conversion efficiency and production rates.     

Semiconductor,molecular and hybrid systems for photoelectrochemical solar fuel production

The paper shortly reviews the basic direct approaches applied in searching for viable solutions to solar fuel production. These are generally distinguished in molecular and semiconductor(non-molecular)systems, however, hybrid strategies, proposed recently, have also been included. The most promising efforts are considered, highlighting key aspects and emerging critical issues. Special attention is paid to aspects such as electrode architecture, device design, and main differences in the scientific vision and challenges to directly produce solar fuels. This overview could be useful to orientate the readers in the wide panorama of research activities concerning water splitting, natural and artificial photosynthesis, and solar fuel production through the identification of common aspects, specialties and potentialities of the many initiatives and approaches that are developing worldwide in this field with the final aim to meet world energy demand.     

Formation of a porphyrin/fullerene light-harvesting system from self-assembly of porphyrin-end-functionalized polycyclohexane and [6,6]-phenyl-C61-butyric acid methyl ester: Effects of microphase separation and π–π interactions

Thin films composed of zinc tetraphenylporphyrin-end-functionalized polycyclohexane (ZnTPP-PCHE) and [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) blends were prepared to investigate their potential as light-harvesting systems within polymer solar cells (PSCs). Both the microphase separation characteristics and the extent of π–π interactions in these ZnTPP-PCHE/PCBM blends had significant effects on the optical properties of the films. The extent to which the absorption bands of the films overlapped the terrestrial solar spectrum was increased considerably when the blends formed a co-continuous structure, even though films of pure ZnTPP-PCHE or PCBM exhibited only weak absorption over that wavelength region. We conclude that these polymer blend films may be considered as viable candidates for light-harvesting systems within PSCs. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

Electron transport in nanostructured metal-oxide semiconductors

Nanostructured films of metal-oxide semiconductors are the focus of intensive research nowadays due to their applications in the current quest for new sources of clean energy. Metal-oxides like TiO₂ and ZnO can be used to make efficient photoanodes for photoelectrochemical solar cells and nanostructured substrates for photocatalytic production of non-polluting fuels. In these applications electron transport through the nanostructure is crucial to achieve a good photon-to-electron quantum efficiency. In this paper the current knowledge of the electron transport mechanisms that take place in these systems is reviewed, highlighting the influence of energy and morphological disorder on the efficacy of the transport process. A special connection is made between the specificity of the electron transport in these systems and their applications in solar cells and photocatalytic devices.     

Impact of ligand modification on hydrogen photogeneration and light-harvesting applications using cyclometalated iridium complexes

To explore structure-activity relationships with respect to light-harvesting behavior, a family of bis-cyclometalated iridium complexes [Ir(C^N)(2)(Hbpdc)] 2-5 (where C^N = 2-phenylbenzothiazole and its functionalized derivatives, and H(2)bpdc =2,2'-bipyridine-4,4'-dicarboxylate) was synthesized using a facile method. The photophysical and electrochemical properties of these complexes were investigated and compared to those of analogue 1 (C^N = (4-trifluoromethyl)-2-phenylbenzothiazole); they were also investigated theoretically using density functional theory. The molecular structures of complexes 2-4 were determined by X-ray crystallography, which revealed typical octahedral coordination geometry. The structural modifications involved in the complexes were accomplished through the attributes of electron-withdrawing CF(3) and electron-donating NMe(2) substituents. The UV-vis spectra of these species, except for that of 5, displayed a broad absorption in the low-energy region, which originated from metal-to-ligand charge-transfer transitions. These complexes were found to exhibit visible-light-induced hydrogen production and light-to-electricity conversion in photoelectrochemical cells. The yield of hydrogen production from water using these complexes was compared, which revealed substantial dependences on their structures, particularly on the substituent of the cyclometalated ligand. Among the systems, the highest turnover number of 1501 was achieved with complex 2, in which the electron-withdrawing CF(3) substituent was connected to a phenyl ring of the cyclometalated ligand. The carboxylate anchoring groups made the complexes highly suitable for grafting onto TiO(2) (P25) surfaces for efficient electron transfer and thus resulted in an enhancement of hydrogen evolution compared to the unattached homogeneous systems. In addition, the combined incorporation of the electron-donating NMe(2) group and the electron-withdrawing CF(3) substituent on the cyclometalated ligand caused complex 5 to not work well for hydrogen production. Their incorporation, however, enhanced the performance of 5 in the light-harvesting application in nanocrystalline TiO(2) dye-sensitized solar cells, which was attributed to the intense absorption in the visible region.     

A novel low-molecular-mass gelator with a redox active ferrocenyl group: tuning gel formation by oxidation

A novel low-molecular-mass gelator containing a redox-active ferrocenyl group, cholesteryl glycinate ferrocenoylamide (CGF), was intentionally designed and prepared. It was demonstrated that the gelator gels 13 out of the 45 solvents tested. Scanning electron microscopy (SEM) measurements revealed that the gelator self-assembled into different supramolecular network structures in different gels. Chemical oxidation of the ferrocenyl residue resulted in phase transition of the gel from gel state to solution state. FTIR and (1)H NMR spectroscopy studies revealed that hydrogen bonding between the gelator molecules in the gel was one of the main driving forces for the formation of the gels.     

Solar energy conversion from water photolysis by biological and chemical systems

The production of chemicals and fuels, or energy-rich compounds, from water by sunlight is described as a particularly attractive means for the conversion of solar energy to a valuable renewable resource. The redox properties of photoexcited molecules and the operating mechanism of light-driven systems are first considered. The mechanism of water oxidation carried out by higher plants and green algae-which is actually one of the most important biochemical reactions—as well as that of artificial photosystems, up-to-now designed trying to simulate the natural process with higher efficiency and simplicity, are likewise discussed. A number of biological and chemical light-driven systems are presented as practical ways to solar energy conversion.     

An Efficient Near-Infrared Emissive Artificial Supramolecular Light-Harvesting System for Imaging in the Golgi Apparatus

Light-harvesting systems are an important way for capturing, transferring and utilizing light energy. It remains a key challenge to develop highly efficient artificial light-harvesting systems. Herein, we report a supramolecular co-assembly based on lower-rim dodecyl-modified sulfonatocalix[4]arene (SC4AD) and naphthyl-1,8-diphenyl pyridinium derivative (NPS) as a light-harvesting platform. NPS as a donor shows significant aggregation induced emission enhancement (AIEE) after assembling with SC4AD. Upon introduction of Nile blue (NiB) as an acceptor into the NPS-SC4AD co-assembly, the light-harvesting system becomes near-infrared (NIR) emissive (675 nm). Importantly, the NIR emitting NPS-SC4AD-NiB system exhibits an ultrahigh antenna effect (33.1) at a high donor/acceptor ratio (250:1). By co-staining PC-3 cells with a Golgi staining reagent, NBD C₆-ceramide, NIR imaging in the Golgi apparatus has been demonstrated using these NIR emissive nanoparticles.