Photocatalysis offers a promising approach for renewable energy conversion and storage, but short lifetimes of charge-separated states in photocatalysts due to charge recombination limit its utility. Here we report an organic molecule with an acceptor–donor–acceptor configuration that can self assemble into highly crystalline nanoparticles. Transient absorption spectroscopy reveals that these crystalline assemblies can induce an ultra-long-lived charge-separated state of up to 1.2 s, attributed to initial symmetry-breaking charge separation, followed by charge hopping across closely packed molecules. These self-assembled nanoparticles have an impressive photocatalytic H₂ evolution rate of 126 mmol g⁻¹ h⁻¹ with an external quantum efficiency of 12% at 550 nm under optimized conditions. This system shows a remarkable stability with 220 million turnover numbers (per particle) over the 77 h of operation. These findings suggest that rational design of organic molecules and their aggregates is vital for improving light-induced charge separation and for developing highly efficient, stable and scalable organic photocatalysts.

The investigation of dyes in perovskite solar cells (PSCs) is an emerging field, since dyes may introduce a range of effects beyond conventional light harvesting. However, the large number of possible materials and processing combinations make systematic investigation challenging. This study presents a hybrid and transferable strategy combining automated workflows and supporting manual evaluation to gain insights into the effects of dyes in PSCs. Using a near-infrared (NIR) dye and a typical lead halide perovskite, an automated synthesis-characterization workflow is demonstrated to be suitable for the evaluation of the effects of a dye either as a precursor additive or as a post-treatment material using photoluminescence as the key performance parameter. In addition, the automated synthesis-device fabrication-evaluation workflow can provide guidance for identifying a suitable concentration range of dye additives in precursor solutions. Computational results at density-functional theory (DFT) level and manually performed experiments suggest that the dye MK245 interacts with the perovskite and modifies its local or interfacial electronic environment. Integration of MK245 can significantly improve the device stability both in mesoscopic triple-layer perovskite solar cells and in conventional thin-film solar cells.

We have developed two new star-shaped donor–acceptor oligomers, named TxBT and TxNT, with a truxene donor core and either 2,1,3-benzothiadiazole (BT) or a naphtho[1,2-c:5,6-c′]bis[1,2,5]thiadiazole (NT) unit, respectively. Femtosecond transient absorption spectroscopy suggested that both oligomer nanoparticles (NPs) generate long-lived triplet charge-transfer (CT) states following photoexcitation, which undergo reductive quenching by ascorbate. TxNT NPs generate a larger population of reduced species that accumulate and escape recombination compared to TxBT NPs, indicating more efficient charge separation. TxNT NPs show significantly higher hydrogen evolution rate (54 mmol h⁻¹ g⁻¹) compared to TxBT NPs, which is comparable to the performance of the most efficient heterojunction polymer NP systems. Additionally, morphological analysis revealed that Pt deposition was significantly lower on TxBT than on TxNT NPs. These findings highlight the critical role of triplet CT states, tuning molecular energy levels, optimizing excited-state dynamics, and engineering NP architecture to increase photocatalytic hydrogen evolution of organic photocatalysts. To our knowledge, this is the first report where triplet CT states can mediate photocatalytic hydrogen evolution in donor–acceptor oligomer NPs.

The urgent need for renewable energy solutions requires rapid advancements in materials discovery. In response, we present AURORA, an innovative robotic platform that enhances this process by integrating automated synthesis, characterization, and evaluation into a single unit, thereby improving efficiency and reducing errors. Its modular design allows for adaptable screening of diverse materials, including metal halide perovskites, and their application in solar cell devices. Our study demonstrates the ability of AURORA to autonomously synthesize and evaluate polycrystalline, mixed halide perovskites, including a novel mesoscopic solar cell array with improved data reliability and throughput. AURORA also conducts postsynthesis treatments and dynamic analyses under stress, setting it apart from traditional methods. These features make AURORA a transformative tool for the discovery of novel materials, with potential machine learning integration for optimization. Our results highlight the application of AURORA as a robust and adaptable platform for future developments in automated materials research. 

The most efficient and stable perovskite solar cells typically contain lead compounds as a key component in the light-absorbing layer. To advance the commercialization of perovskite photovoltaics, it is crucial to address sustainability concerns regarding the use of toxic lead. In this work, we have developed a straightforward lead recycling pathway that converts lead compounds from lead–acid batteries into lead iodide. Purity analyses of the resulting lead iodide and the direct fabrication of perovskite solar cells demonstrate that the recycled lead iodide matches the quality of commercially available products. Most importantly, establishing this efficient lead recycling process not only supports sustainable recycling and resource utilization in a circular materials flow but also promotes the future development of perovskite photovoltaics.

Organic-inorganic hybrid materials based on lead and bismuth have recently been proposed as novel X- and gamma-ray detectors for medical imaging, non-destructive testing, and security, due to their high atomic numbers and facile preparation compared to traditional materials like amorphous selenium and Cd(Zn)Te. However, challenges related to device operation, excessively high dark currents, and long-term stability have delayed commercialization. Here, two novel semiconductors incorporating stable sulfonium cations are presented, [(CH3CH2)3S]6Bi8I30 and [(CH3CH2)3S]AgBiI5, synthesized via solvent-free ball milling and fabricated into dense polycrystalline pellets using cold isostatic compression, two techniques that can easily be upscaled, for X-ray detection application. The fabricated detectors exhibit exceptional sensitivities (14 100-15 190 mu C Gyair-1 cm-2) and low detection limits (90 nGyair s-1 for [(CH3CH2)3S]6Bi8I30 and 78 nGyair s-1 for [(CH3CH2)3S]AgBiI5), far surpassing current commercial detectors. Notably, they maintain performance after 9 months of ambient storage. The findings highlight [(CH3CH2)3S]6Bi8I30 and [(CH3CH2)3S]AgBiI5 as scalable, cost-effective and highly stable alternatives to traditional semiconductor materials, offering great potential as X-ray detectors in medical and security applications.

Polymerization isomerism is potentially important for metal alkoxides as precursors of oxide materials. Here, we present this phenomenon for tungsten oxo-methoxide, reporting the molecular and crystal structure of its polymeric form [WO(OMe)4]∞(1), its dimeric form W2O2(OMe)8(2), and a higher extent oxo-substituted by-product of the synthesis, Li2(MeOH)6W12O29(OMe)16(3).

Natural photosynthesis plays a vital role in the supply of energy and oxygen necessary for the survival of biological organisms. The current leading proposal of the O-O bond formation in photosystem II suggests the coupling between the central mu-oxo (O5) and the additional oxygenic ligand (Ox) of the manganese-calcium oxide cofactor. However, the subsequent process through which molecular dioxygen is formed and released remains elusive. In this report, quantum chemical calculations reveal that the O-2 release process is initiated by the cleavage of the Mn-O5 bond, without a preliminary conformational change of the peroxide [O5-Ox](2-) group. Subsequently, the [O5-Ox] moiety is converted from the superoxide to the weakly bound quasi-O-2 where the Mn-Ox bond is cleaved, and after a twist of the quasi-O-2 unit, the free O-2 is ultimately released. Alternative pathways display significantly slower kinetics, due to the lower structural stabilities of the rate-limiting transition states. The cause of the difference is associated with the Jahn-Teller axial orientation and the local ring strain within the Mn cluster. These findings contribute to unravelling the intricate mechanism involved in an important step of photosynthetic oxygen evolution for a deeper understanding of nature's water oxidation catalysis.

The energy‐generating charge transportation in dye sensitized solar cells (DSSCs) occurs at the photoanode interface, and degradation at the interface can severely impact the cell performance. The study investigates the degradation of DSSCs and the main factors causing the decrease in cell performance over time. The DSSCs investigated here maintain their stability in the dark but upon light exposure, the cell degraded. The surface‐sensitive techniques X‐ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and neutral impact collision ion scattering spectroscopy (NICISS) are employed to investigate the change in the elemental and chemical composition at the electrode interface. Fourier transform infrared spectroscopy (FTIR) is applied to investigate the change in functional groups throughout the dye TiO 2 interface. The XPS and NICISS results confirm the penetration of I x − ( x = 1 or 3) species into the dye layer as the main reason for cell degradation. FTIR and UV–vis DRS show the interaction of electrolytes with the dye molecule resulting in changes in the dye structure under light resulting in cell degradation. The main reason for the cell degradation observed is the penetration of I x − into the dye layer which further instigates changes in the dye molecule affecting the light absorption ability of the dye and thus, decreasing the generation of photoelectrons resulting in poor performance of the cell over time.