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All-in-one photosynthetic assemblies for solar fuels
摘要： Converting solar energy into chemical fuel using an all-in-one photosynthetic assembly requires novel concept and cutting-edge technologies. Up to now, a series of new concepts have been suggested for designing of the assembly. It is thus important to examine present physics and research status of the assembly to glean the design guidelines for future devices. Here we introduce the concept of all-in-one photosynthetic assembly, which including photoelectrochemical diodes, all-in-one membranes and monolithic photovoltaic-photoelectrolysis cells. Key physical aspects are examined to identify the state-of-the-art in device design. We then discuss the device configurations, requirements and practical implications. Key features of the assemblies are also highlighted with their photosynthetic performance. Finally, a potential design that can be scalable to large area is projected for a more complete picture of the field. These concepts and their successful realization will be an important contribution towards realization of artificial photosynthesis.
关键词： Photochemical cells,All-in-one,Device,Artificial photosynthesis,Solar fuels
更新于2025-09-23 15:21:01
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Efficient photocatalytic synthesis of l-glutamate using a self-assembled carbon nitride/sulfur/porphyrin catalyst
摘要： Mimicking natural photosynthesis is a promising way to produce fine chemicals, yet there is a need for efficient catalysts. Here, we synthesized a photocatalyst made of self-assembled graphitic carbon nitride/sulfur/cobalt (III) tetraphenyl porphyrin, and we used this photocatalyst for production of the l-glutamate amino acid in 93.6% yield. Regeneration of the 1,4-dihydronicotinamide adenine dinucleotide cofactor under visible light reached 88.3%.
关键词： Graphitic carbon nitride/sulfur/cobalt (III) tetraphenyl porphyrin photocatalyst,Mimicking natural photosynthesis,Amino acid (l-glutamate) production,1,4-Dihydronicotinamide adenine dinucleotide cofactor regeneration
更新于2025-09-23 15:19:57
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Spin-Controlled Charge Recombination Pathways across the Inorganic/Organic Interface
摘要： Charge transfer and recombination across the inorganic/organic interface in nanocrystal or quantum dot (QD)-molecule hybrid materials has been extensively studied. Principles of controlling charge transfer and recombination via energetics and electronic coupling have been established. However, the use of electron spin to control transfer and recombination pathways in such systems remains relatively underexplored. Here we use CdS QD-alizarin (AZ) as a model system to demonstrate this principle. Using time-resolved spectroscopy, we found that the charge separated states (QD--AZ+) created by selectively exciting AZ molecules mostly recombined to regenerate ground state complexes, whereas the apparently “same” charge separated states created by exciting QDs recombined to produce AZ molecular triplet states. Such a difference can be traced to the distinct spin configurations between excited QDs (QD*, with an ill-defined spin) and AZ (1AZ*, spin singlet) and the asymmetric electron and hole spin-flip rates in II-VI group QDs. The transferability of such a principle was confirmed by similar observations obtained for CdS QD-tetracene complexes. Opening an avenue of controlling charge transfer and recombination pathways via electron spin is potentially important for applications such as artificial photosynthesis.
关键词： CdS QD-alizarin,artificial photosynthesis,quantum dot,inorganic/organic interface,triplet states,electron spin,recombination,time-resolved spectroscopy,Charge transfer
更新于2025-09-23 15:19:57
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Optical properties of corals distort variable chlorophyll fluorescence measurements
摘要： Pulse amplitude modulated (PAM) fluorimetry is widely used in photobiological studies of corals, as it rapidly provides numerous photosynthetic parameters to assess coral ecophysiology. Coral optics studies have revealed the presence of light gradients in corals, which are strongly affected by light scattering in coral tissue and skeleton. We investigated whether coral optics affects variable chlorophyll fluorescence measurements and derived photosynthetic parameters by developing planar hydrogel slabs with immobilized microalgae and with bulk optical properties similar to those of different types of corals. Our results show that PAM-based measurements of photosynthetic parameters differed substantially between hydrogels with different degrees of light scattering but identical microalgal density, yielding deviations in apparent maximal electron transport rates by a factor of 2. Furthermore, system settings such as the measuring light intensity affected F0, Fm and Fv/Fm in hydrogels with identical light absorption but different degrees of light scattering. Likewise, differences in microalgal density affected variable chlorophyll fluorescence parameters, where higher algal densities led to greater Fv/Fm values and relative electron transport rates. These results have important implications for the use of variable chlorophyll fluorimetry in ecophysiological studies of coral stress and photosynthesis, as well as other optically dense systems such as plant tissue and biofilms.
关键词： light scattering,PAM fluorimetry,photosynthesis,hydrogels,variable chlorophyll fluorescence,coral optics
更新于2025-09-19 17:15:36
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When Does Organic Photoredox Catalysis Meet Artificial Photosynthesis?
摘要： The basics of photocatalysis are under investigation for more than a century. Contemporary science maintains an emphasis on fundamental studies, but application-oriented research in solar energy conversion, environmental remediation, light-promoted chemical synthesis and medicinal phototherapy is growing rapidly. These prospects have triggered a renaissance of the field and breath-taking progress has been made in the last decade by chemists from all major branches. Artificial photosynthesis aims to produce a renewable fuel using sunlight. This 'solar fuel' is thereby synthesized from the reduction of water or carbon dioxide, coupled to the oxidation of a substrate; typically, water to O2. The underlying endothermic multi-electron/multi-proton chemistry is relatively well understood, but the assembly of a commercially viable device remains elusive due to the 'low' market-value of chemical fuels. Photoreforming can decompose organics such as waste biomass (lignocellulose), plastics or pollutants to produce a fuel using solar irradiation. This process has overall a much-reduced thermodynamic barrier compared to overall water splitting, but suffers from a kinetically challenging reaction, insufficient solubility of polymeric substrate or low concentration of pollutants. Organic photoredox catalysis uses light to accelerate chemical reactions by well-controlled single-electron redox events. This radical chemistry approach has not only allowed for improved synthetic procedures, but also new transformations to proceed. The value-added organic products are synthesized in controlled laboratory environments, usually using LED lamps. Although photocatalysis is of growing interest to the chemical and pharmaceutical industry, large-scale processes have rarely been implemented. Medicinal chemistry develops light sensitive medication for the destruction of abnormal cells. In photodynamic therapy, the photosensitizer drug is irradiated using a defined wavelength and reacts with O2 to produce reactive oxygen species to exert phototoxicity. Achieving high quantum yields and the development of red (or near IR) light absorbers (for improved skin penetration) are common objectives with artificial photosynthesis (for optimal solar light harvesting). Although the same basics of photochemistry unite these applications, they are being developed in surprising isolation as inorganic and physical chemists focus on artificial photosynthesis, chemical engineers on photoreformation, organic chemists on photoredox catalysis, and medicinal chemists on photodynamic therapy. This divide is cemented by separating the scientists often in different institutes, teaching structures and firmly placing them in separate academic communities. This editorial is intended as a call to join forces and embrace progress in all of these areas to enable accelerated development of a more holistic science in photocatalysis. There is plenty we can learn from each other as we share mutual interests and common goals. The quickly developing pool of environmentally benign, robust, non-toxic, scalable and efficient photocatalysts for solar fuel synthesis provides vast opportunities for improved and new organic catalysis. For example, heterogeneous photocatalysts such as semiconductor powders and photoelectrochemical architectures are rarely employed in organic chemistry. Time-resolved spectroscopy can provide in-depth understanding of electron transfer dynamics and insights into organic mechanisms. Proton-coupled multi-electron and endothermic photochemistry may pave the way to currently inaccessible organic chemistry. Coupling of solar fuel synthesis to value added oxidation chemistry for bulk or even fine chemical synthesis is a largely untapped territory (Figure 1). The simultaneous production of a chemical fuel and value-added organic improves the economics in artificial photosynthesis and may accelerate market penetration for solar fuels. Understanding organic transformations and industrial processes allows the selection of meaningful alternatives to water oxidation. Clean organic oxidations with high selectivity and conversion yield are key criteria to distinguish them from the use of undesirable sacrificial electron donors. It may be true that we cannot produce enough fuel to power the planet by coupling fuel synthesis to organic chemistry, but it is nevertheless an attractive entry point for commercialisation as well as a rich intellectual playground for academic research. Photoreforming can be exploited for simultaneous fuel production and chemical synthesis from an organic waste substrate, thereby addressing the issues of renewable energy generation and sustainable chemical synthesis with environmental remediation. Agricultural and plastic waste are a valuable resource that should not go to landfills. It contains stored energy and useful chemical building blocks for chemical transformations. Photoreformation of lignocellulose and plastics has been demonstrated to provide access to clean H2 fuel as well as organic chemicals. A final question concerns the use of sunlight versus electrical (LED) irradiation and this will ultimately depend on the application. The common view is that the synthesis of organics will be performed in the laboratory using LEDs, whereas fuel production requires large land-areas and therefore sunlight. But there are plenty of alternative possibilities and scenarios to challenge this traditional view. Could the drop in renewable (solar) electricity production may ultimately make fuel synthesis with efficient LEDs possible? Why not consider swimming-pool sized flow-reactors powered by the sun for bulk chemical production or solar-concentrators for greener organic synthesis? Solar-driven chemistry can also give access to off-grid synthesis of fertilisers, medicine, and commodities in remote areas and sun-rich developing countries. Some of these suggestions may indeed appear naive, but cross-fertilisation and an open mind will ultimately provide the basis for new developments in photocatalysis.
关键词： photocatalysis,photosynthesis,organocatalysis,solar fuels,redox chemistry
更新于2025-09-19 17:15:36
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Structure-activity relationships of hierarchical three-dimensional electrodes with photosystem II for semi-artificial photosynthesis
摘要： Semi-artificial photosynthesis integrates photosynthetic enzymes with artificial electronics, which is an emerging approach to reroute the natural photoelectrogenetic pathways for sustainable fuel and chemical synthesis. However, the reduced catalytic activity of enzymes in bioelectrodes limits the overall performance and further applications in fuel production. Here, we show new insights into factors that govern the photoelectrogenesis in a model system consisting of photosystem II and three-dimensional indium tin oxide and graphene electrodes. Fluorescence microscopy and in situ surface-sensitive infrared spectroscopy are employed to probe the enzyme distribution and penetration within electrode scaffolds of different structures, which is further correlated with protein film-photoelectrochemistry to establish relationships between the electrode structure and enzyme activity. We find that the hierarchical structure of electrodes mainly affects the protein integration, but not the enzyme activity. Photoactivity is more limited by light intensity and electronic communication at the biointerface. This study provides guidelines for maximizing the performance of semi-artificial photosynthesis and also presents a set of methodologies to probe the photoactive biofilms in three-dimensional electrodes.
关键词： semi-artificial photosynthesis,Photosystem II,inverse opal,graphene electrode,indium tin oxide electrode
更新于2025-09-19 17:15:36
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Industrial Applications of Nanomaterials || Nanotechnology for biological photovoltaics; industrial applications of nanomaterials
摘要： This chapter describes the importance and use of nanotechnology for BPVs. Biological photovoltaics are solar energy conversion systems which are producing electricity based on the photosynthesis reaction takes place in thylakoid membrane. The process of collecting energy from BPV has been studied by the researchers to obtain highly efficient systems. For this reason, number of reports based on the BPVs, which focuses on direct and indirect electricity generation using soluble conductive mediators, has been published. Successful results reveal that these systems can convert sunlight into electricity, but there are some points to increase efficiency. The application of nanomaterials combined with BPV has shown tremendous improvement on the power output of BPV systems. Creating functional surfaces that “wiring” more biological components into the electrode was one of the first steps in nanotechnological advances to BPV systems. Large surface area according to the volume ratio makes anode and cathode electrodes more efficient in applications which is the another main improvement. The potential role of nanomaterials such as carbon nanotube and graphene has been studied with BPV for small and large-scale applications, highlighting the importance and application of green energy production. The electron transport mechanism in cyanobacteria and algae is well known, and the transformation of the newly designed systems into the photovoltaic device by means of nanomaterials with the aid of nanomaterials in the conversion of light into energy has also been shown. The results show that nanotechnology improves the energy conversion rate of BPV systems. It is foreseen that energy exchange rates will increase further with nanomaterial applications and the studies will continue toward industrial applications.
关键词： Nanomaterials,Nanotechnology,Electron transport mechanism,Biological photovoltaics,Photosynthesis,Green energy
更新于2025-09-19 17:13:59
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Synthesis and properties of a novel porphyrin–fullerene triad assembled through donor–acceptor bonding
摘要： Complexation of (hydroxy)(oxo)(5,10,15,20-tetraphenylporphyrinato) molybdenum(v) with 2',5'-di(2-pyridyl)-1'-(3-pyridyl methyl)pyrrolidino[70]fullerene leading to a new donor–acceptor triad is characterized by quantitative description of the equilibrium and the reaction rate. The prospects of the triad as a photosynthetic antenna imitator and an active layer in solar energy conversion devices are substantiated.
关键词： solar energy conversion,porphyrin–fullerene triad,donor–acceptor bonding,photosynthesis
更新于2025-09-16 10:30:52
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High throughput procedure utilising chlorophyll fluorescence imaging to phenotype dynamic photosynthesis and photoprotection in leaves under controlled gaseous conditions
摘要： Background: As yields of major crops such as wheat (T. aestivum) have begun to plateau in recent years, there is growing pressure to efficiently phenotype large populations for traits associated with genetic advancement in yield. Photosynthesis encompasses a range of steady state and dynamic traits that are key targets for raising Radiation Use Efficiency (RUE), biomass production and grain yield in crops. Traditional methodologies to assess the full range of responses of photosynthesis, such a leaf gas exchange, are slow and limited to one leaf (or part of a leaf ) per instrument. Due to constraints imposed by time, equipment and plant size, photosynthetic data is often collected at one or two phenological stages and in response to limited environmental conditions. Results: Here we describe a high throughput procedure utilising chlorophyll fluorescence imaging to phenotype dynamic photosynthesis and photoprotection in excised leaves under controlled gaseous conditions. When measured throughout the day, no significant differences (P > 0.081) were observed between the responses of excised and intact leaves. Using excised leaves, the response of three cultivars of T. aestivum to a user—defined dynamic lighting regime was examined. Cultivar specific differences were observed for maximum PSII efficiency (Fv′/Fm′—P < 0.01) and PSII operating efficiency (Fq′/Fm′—P < 0.04) under both low and high light. In addition, the rate of induction and relaxation of non-photochemical quenching (NPQ) was also cultivar specific. A specialised imaging chamber was designed and built in-house to maintain gaseous conditions around excised leaf sections. The purpose of this is to manipulate electron sinks such as photorespiration. The stability of carbon dioxide (CO2) and oxygen (O2) was monitored inside the chambers and found to be within ± 4.5% and ± 1% of the mean respectively. To test the chamber, T. aestivum ‘Pavon76’ leaf sections were measured under at 20 and 200 mmol mol?1 O2 and ambient [CO2] during a light response curve. The Fv′/Fm′was significantly higher (P < 0.05) under low [O2] for the majority of light intensities while values of NPQ and the proportion of open PSII reaction centers (qP) were significantly lower under > 130 μmol m?2 s?1 PPFD. Conclusions: Here we demonstrate the development of a high-throughput (> 500 samples day?1) method for phenotyping photosynthetic and photo-protective parameters in a dynamic light environment. The technique exploits chlorophyll fluorescence imaging in a specifically designed chamber, enabling controlled gaseous environment around leaf sections. In addition, we have demonstrated that leaf sections do not different from intact plant material even > 3 h after sampling, thus enabling transportation of material of interest from the field to this laboratory based platform. The methodologies described here allow rapid, custom screening of field material for variation in photosynthetic processes.
关键词： Dynamic,Imaging,Phenotyping,Wheat,Photo-protection,Photosynthesis,Chlorophyll fluorescence
更新于2025-09-16 10:30:52
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Light-Driven Redox Activation of CO <sub/>2</sub> - and H <sub/>2</sub> -Activating Complexes in a Self-Assembled Triad
摘要： We report a self-assembled triad for artificial photosynthesis comprised of a chromophore, carbon-dioxide reduction catalyst, and hydrogen-oxidation complex, which is designed to operate without conventional sacrificial redox equivalents. Excitation of the zinc–tetraphenylporphyrin chromophore of the triad results in ultrafast charge transfer between a tungsten–alkylidyne donor and a rhenium diimine tricarbonyl acceptor, producing a charge-separated state that persists on the timescale of tens of nanoseconds and is thermodynamically capable of the primary dihydrogen and carbon dioxide binding steps for initiating the reverse water-gas shift reaction. The charge-transfer behavior of this system was probed using time-resolved fluorescence and transient absorption spectroscopy in the visible, near-infrared, and mid-infrared spectral regions. The behavior of the triad was compared to that of the zinc porphyrin–rhenium diimide dyad; the triad was found to have a significantly longer charge-separated lifetime than other previously reported porphyrin–rhenium diimine compounds.
关键词： artificial photosynthesis,zinc–tetraphenylporphyrin,charge transfer,reverse water-gas shift reaction,rhenium diimine tricarbonyl,self-assembled triad
更新于2025-09-12 10:27:22