Abstract Natural photosynthetic antennas arrange chromophores at high density without aggregation, concentrating excitation energy at the reaction center with near-unity quantum efficiency. Reproducing this function is a key challenge for delivering light energy to artificial photosynthetic reaction centers. Here we designed a trivalent cationic BODIPY derivative (BODIPY3+) whose molecular size matches the interanionic-site distance (ca. 1.2 nm) of saponite (SSA) clay nanosheets. Through this size-matching effect, BODIPY3+ adsorbed as isolated monomers, without aggregation, up to 81% of the cation exchange capacity (CEC). Fixation on the rigid clay surface suppressed nonradiative deactivation and lengthened the fluorescence lifetime from 0.8 ns in water to 2.0 ns. The Förster equation gave a homoenergy-migration rate constant of kmg = 6.2 × 1010 s–1, more than 2 orders of magnitude faster than the excited-state decay, so the excitation samples on the order of 102 donor molecules within its lifetime. With coadsorbed cationic porphyrin (p-TMPyP) as the acceptor, the energy-transfer efficiency remained ca. 60% even at a donor/acceptor ratio of 48:1─far exceeding a random-distribution model and evidencing multistep migration. This BODIPY3+/clay system functions as an artificial light-harvesting antenna and demonstrates the value of inorganic nanosheets as reaction fields for artificial photosynthesis.
Abstract Photoinduced charge separation is crucial for converting solar energy to electrical and chemical energy. In this work, to improve the photoinduced charge separation efficiency at the photosensitizing dye–semiconductor interface, we synthesized two dual-porphyrin-sensitized Pt-loaded TiO2 nanoparticle photocatalysts (ZnP–Zr–SnP@Pt–TiO2 (DPSP) and SnP–Zr–ZnP@Pt–TiO2 (DPSP-r)) by reversing the loading order of two metalloporphyrin-photosensitizing dyes (SnP and ZnP = 5,10,15,20-tetrakis(p-carboxyphenyl)-porphyrinato-M; M = SnIVCl2, ZnII). The apparent quantum yield of the photocatalytic H2 production reaction over DPSP in a 500 mM l-ascorbic acid sacrificial electron donor aqueous solution (2.08%) was estimated to be approximately 10 times higher than that over DPSP-r (0.21%), indicating the importance of the loading order of the metalloporphyrin dye for efficient photoinduced charge separation. The barely emissive nature of the DPSP compounds and the redox potentials of ZnP and SnP suggested that the redox cascade structure of the dual-metalloporphyrin ZnP–Zr–SnP layer on the Pt–TiO2 nanoparticle surface plays a key role in photoinduced charge separation for photocatalytic H2 production. The combination of this dual-metalloporphyrin sensitization method and the versatility of the metalloporphyrin family promotes the development of highly active visible-light-driven photocatalysts.
Abstract Single-benzene-based fluorophores (SBFs) represent a highly versatile class of minimalistic light-emitting molecules. They exhibit tunable photophysical properties and are biocompatible when they are integrated with biological systems. Thanks to their minimal design and versatile light emission, they are attractive molecules used as fluorescent sensors and as bioimaging probes. Here, we report the design, single-step synthesis, purification, and characterization of three photoluminescent SBF derivatives together with the study of their interactions with model diatom microalgae Thalassiosira weissflogii. The different candidates (bearing (i) a hydrophobic tail chain, (ii) a triethoxysilyl group, and (iii) an amino acid residue) demonstrate distinct interactions with different cellular structures of living diatoms, exhibiting promising characteristics to develop selective bioimaging probes. Moreover, two SBF candidates were found to exert a positive effect on diatom photosynthetic efficiency with an enhancement in biomass production, potentially working as exogenous antennae. Future developments would include the incorporation of these easily accessible dyes in bioimaging, environmental biosensing, and bioengineering aimed at increasing photosynthetic efficiency.
The landscape and status of artificial photosynthesis devices for solar fuels are analyzed by critically combining indications from roadmaps and status reports, patent and literature trends, a market perspective analysis, and an examination of selected ongoing projects in the field. This multifaceted approach aims to provide an innovative vision of opportunities and accelerate their implementation. It integrates insights from multiple perspectives to overcome the partial view of priorities and key elements needed to foster development in the area. Additionally, they include strategies to accelerate implementation from individual analyses. This is recognized as a crucial current gap. Recommendations are provided for aspects that should be introduced to accelerate progress toward significant implementation before 2050, based on this analysis and methodological approach.
