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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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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
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Prediction of sunlight-driven CO2 conversion: Producing methane from photovoltaics, and full system design for single-house application
摘要： CO2 capture and utilization (CCU) technologies are being immensely researched as means to close the anthropogenic carbon cycle. One approach known as artificial photosynthesis uses solar energy from photovoltaics (PV), carbon dioxide and water to generate hydrocarbon fuels, being methane (CH4) a preferential target due to the already in place infrastructures for its storage, distribution and consumption. Here, a model is developed to simulate a direct (1-step) solar methane production approach, which is studied in two scenarios: first, we compare it against a more conventional 2-step methane production route, and second, we apply it to address the energetic needs of concept buildings with usual space and domestic hot water heating requirements. The analysed 2-step process consists in the PV-powered synthesis of an intermediate fuel e syngas e followed by its conversion to CH4 via a Fischer eTropsch (methanation) process. It was found that the 1-step route could be adequate to a domestic, small scale use, potentially providing energy for a single-family house, whilst the 2-step can be used in both small and large scale applications, from domestic to industrial uses. In terms of overall solar-to-CH4 energy efficiency, the 2-step method reaches 13.26% against the 9.18% reached by the 1-step method. Next, the application of the direct solar methane technology is analysed for domestic buildings, in different European locations, equipped with a combination of solar thermal collectors (STCs) and PV panels, in which the heating needs that cannot be fulfilled by the STCs are satisfied by the combustion of methane synthesized by the PV-powered electrolyzers. Various combinations of situations for a whole year were studied and it was found that this auxiliary system can produce, per m2 of PV area, in the worst case scenario 23.6 g/day (0.328 kWh/day) of methane in Stockholm, and in the best case scenario 47.4 g/day (0.658 kWh/day) in Lisbon.
关键词： Artificial photosynthesis,Fischer-Tropsch synthesis,Photovoltaic-powered electrochemical conversion,Building-integrated solar methane,CO2 electrolysis
更新于2025-09-11 14:15:04
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The Artificial Leaf: Recent Progress and Remaining Challenges
摘要： The prospect of a device that uses solar energy to split water into H2 and O2 is highly attractive in terms of producing hydrogen as a carbon-neutral fuel. In this mini review, key research milestones that have been reached in this field over the last two decades will be discussed, with special focus on devices that use earth-abundant materials. Finally, the remaining challenges in the development of such “artificial leaves” will be highlighted.
关键词： water splitting,hydrogen production,sustainable hydrogen,artificial photosynthesis,electrochemistry
更新于2025-09-10 09:29:36
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Function-integrated Ru catalyst for photochemical CO2 reduction
摘要： Visible-light driven catalytic reduction of CO2 is at the heart of artificial photosynthesis. Here, we demonstrate the first example of a Ru complex that can function both as a photosensitizer and catalyst for CO2 reduction. The catalyst exhibited excellent activity for CO evolution with a high turnover number (TON, 353 for 24 h), reaction rate (TOF, 14.7 h?1), and product selectivity (97%) under visible-light irradiation. We also succeeded in selective product formation (CO or HCOOH) by changing the basicity of the reaction media. This finding will open new avenues for visible-light driven photoredox catalysis using Ru-based function-integrated photocatalysts.
关键词： Ru complex,visible-light,artificial photosynthesis,CO2 reduction,photocatalysis
更新于2025-09-10 09:29:36
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Interface Engineering of Hematite with Nacre-like Catalytic Multilayers for Solar Water Oxidation
摘要： An efficient water oxidation photoanode based on hematite has been designed and fabricated by tailored assembly of graphene oxide (GO) nanosheets and cobalt polyoxometalates (Co-POM) water oxidation catalysts into a nacre-like multilayer architecture on a hematite photoanode. The deposition of catalytic multilayers provides a high photocatalytic efficiency and photoelectrochemical stability to underlying hematite photoanodes. Compared to the bare counterpart, the catalytic multilayer electrode exhibits a significantly higher photocurrent density and large cathodic shift in onset potential (~ 369 mV) even at neutral pH conditions due to the improved charge transport and catalytic efficiency from the rational and precise assembly of GO and Co-POM. Unexpectedly, the polymeric base layer deposited prior to the catalytic multilayers improves the performance even more by facilitating the transfer of photogenerated holes for water oxidation through modification of the flat band potential of the underlying photoelectrode. This approach utilizing polymeric base and catalytic multilayers provides an insight into the design of highly efficient photoelectrodes and devices for artificial photosynthesis.
关键词： photocatalysis,graphene oxide,layer-by-layer assembly,artificial photosynthesis,polyoxometalate
更新于2025-09-10 09:29:36
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Hierarchical organization of perylene bisimides and polyoxometalates for photo-assisted water oxidation
摘要： The oxygen in Earth’s atmosphere is there primarily because of water oxidation performed by photosynthetic organisms using solar light and one specialized protein complex, photosystem II (PSII). High-resolution imaging of the PSII ‘core’ complex shows the ideal co-localization of multi-chromophore light-harvesting antennas with the functional reaction centre. Man-made systems are still far from replicating the complexity of PSII, as the majority of PSII mimetics have been limited to photocatalytic dyads based on a 1:1 ratio of a light absorber, generally a Ru–polypyridine complex, with a water oxidation catalyst. Here we report the self-assembly of multi-perylene-bisimide chromophores (PBI) shaped to function by interaction with a polyoxometalate water-oxidation catalyst (Ru4POM). The resulting [PBI]5Ru4POM complex shows a robust amphiphilic structure and dynamic aggregation into large two-dimensional paracrystalline domains, a redshifted light-harvesting efficiency of >40% and favourable exciton accumulation, with a peak quantum efficiency using ‘green’ photons (λ?>?500?nm). The modularity of the building blocks and the simplicity of the non-covalent chemistry offer opportunities for innovation in artificial photosynthesis.
关键词： polyoxometalates,water oxidation,artificial photosynthesis,photo-assisted,perylene bisimides
更新于2025-09-10 09:29:36
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A Mechanistic View of the Main Current Issues in Photocatalytic CO2 Reduction
摘要： After 40 years of research on photocatalytic CO2 reduction, there are still many unknowns about its mechanistic aspects even for the most common TiO2-based photocatalytic systems. These uncertainties include the pathways inducing visible-light activity in wide-band-gap semiconductors; the charge transfer between semiconductors and plasmonic metal nanoparticles; the unambiguous determination of the origin of C-bearing products; the very first step in the activation of the CO2 molecule; the factors determining the selectivity; the reasons of photocatalyst deactivation; the closure of the catalytic cycle by the hole-scavenging reagent; and the detailed reaction pathways and the most suitable techniques for their determination. This perspective discusses these controversial issues based on the most relevant investigations reported so far. For that purpose, we have tried to view the complex CO2 reduction in a holistic manner, considering today’s state-of-the-art approaches, strategies and techniques for the study of one of the hottest topics in energy research.
关键词： Advanced characterization techniques,CO2 reduction,Photocatalysis,Artificial photosynthesis,Reaction mechanism,Charge transfer
更新于2025-09-04 15:30:14