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A deep understanding of the dynamics of photogenerated charge carriers is extremely important for promoting their germination in semiconductors to enhance the efficiency of solar energy conversion. In contrast to that of organic molecular heterojunctions (which are widely employed in organic solar cells), the charge transfer dynamics of purely inorganic molecular heterojunctions remains unexplored. Herein, we reveal the dynamics of charge transfer between inorganic semiconductor molecular heteroclusters by selecting a group of open-framework metal chalcogenides as unique structure models constructed from supertetrahedral T3-InS ([In10S20]) and T4-MInS ([M4In16S35], M = Mn or Fe) clusters. The staggered band gap alignment in T3-T4-MInS molecular heterojunctions enables the photogenerated charge carriers to be directionally transferred from T3-InS clusters to adjacent T4-MInS clusters upon irradiation or application of an external electric field. The simultaneous independence of and interactions between such two heteroclusters are investigated by theoretical calculations, steady- and transient-state absorption/photoluminescence spectroscopy, and surface photovoltage analysis. Moreover, the dynamics of cluster-to-cluster-to-dopant photogenerated charge transfer is deliberately elucidated. Thus, this work demonstrates the direct observation of charge transfer between molecular heterojunctions based on purely inorganic semiconductor clusters and is expected to promote the development of cluster-based semiconductors for solar cells.

Polymer–polymer blends have been reported to exhibit exceptional thermal and ambient stability. However, power conversion efficiencies (PCEs) from devices using polymeric acceptors have been recorded to be significantly lower than those based on conjugated molecular acceptors. Herein, two organic nonfullerene bulk heterojunction (BHJ) blends ITIC:PBDB-T and N2200:PBDB-T, together with their fullerene counterpart, PCBM:PBDB-T, are adopted to understand the effect of electron acceptors on device performance. Free charge carrier properties using time-resolved microwave conductivity (TRMC) measurements are comprehensively investigated. The nonfullerene devices show an improved PCE of 10.06% and 6.65% in the ITIC- and N2200-based cells, respectively. In comparison, the PCBM:PBDB-T-based devices yield a PCE of 5.88%. The optimal N2200:PBDB-T produced the highest TRMC mobility, longest lifetime, and greatest free-carrier diffusion length. It is found that such phenomena can be associated with the unfavorable morphology of the all-polymer BHJ microstructure. In contrast, the solar cells using either the PCBM or ITIC acceptors display a more balanced donor and acceptor phase separation, leading to more efficient free-carrier separation and transport in the operating device. By sacrificing efficiency for superior stability, it is shown that the improved structure in all-polymer blend can deliver a more stable morphology under thermal stress.

It is highly desirable, while still challenging, to obtain noble metal nanocrystals with custom capping ligands, because their colloidal synthesis relies on specific capping ligands for the shape control while conventional ligand exchange processes suffer from "the strong replaces the weak" limitation, which greatly hinders their applications. Herein, we report a general and effective ligand exchange approach that can replace the native capping ligands of noble metal nanocrystals with virtually any type of ligands, producing flexibly tailored surface properties. The key is to use diethylamine with conveniently switchable binding affinity to the metal surface as an intermediate ligand. As a strong ligand, it in its original form can effectively remove the native ligands; while protonated, it loses its binding affinity and facilitates the adsorption of new ligands, especially weak ones, onto the metal surface. By this means, the irreversible order in the conventional ligand exchange processes could be overcome. The efficacy of the strategy is demonstrated by mutual exchange of the capping ligands among cetyltrimethylammonium, citrate, polyvinylpyrrolidone, and oleylamine. This novel strategy significantly expands our ability to manipulate the surface property of noble metal nanocrystals and extends their applicability to a wide range of fields, particularly biomedical applications.

Trimethylamine borane (TMAB, (CH3)3N·BH3) is widely used as a reliable precursor in various chemical syntheses and has a theoretical hydrogen content of 16.6 wt%, making it a potential candidate for hydrogen storage. Exploring materials under high pressure provides key insights into their structural stability and phase transformations, which are crucial for their design, synthesis, and practical application. In this work, we report the first high-pressure study on TMAB, investigating its structural stability, pressure-induced phase transition, bonding, and electronic properties up to 35 GPa using a comprehensive approach combining vibrational spectroscopy, X-ray diffraction (XRD), evolutionary crystal structure prediction, and density functional theory (DFT). The results indicate that TMAB exhibits an unprecedented high-pressure stability up to nearly 9 GPa, above which it undergoes a phase transition from the R3m phase to a P31 phase. The absence of N–H⋯H–B dihydrogen bonds significantly contributes to the robust stability of TMAB, making it suitable for further high-pressure applications and as a stable precursor under extreme conditions. Detailed analysis of TMAB's pressure-dependent crystal lattice parameters, unit-cell volumes and bulk moduli highlights its compressibility, while changes in its electronic band gap suggest improved conductive properties at higher pressures. Our findings provide new insights into the structural, bonding, and electronic properties of TMAB that are essential for its advanced applications. [ABSTRACT FROM AUTHOR]

Urea oxidation reaction (UOR) features a lower overpotential compared to the oxygen evolution reaction (OER) during electrolysis, facilitating the hydrogen evolution reaction (HER) at the cathode. The distribution of charge plays a pivotal role in promoting the adsorption and cleavage of chemical groups in urea molecules, which can be modulated by introducing a heterostructure. Herein, a CoS1.097/Ni3S2 heterojunction grown on nickel foam is designed, serving simultaneously for UOR and HER. Based on density functional theory (DFT) calculations, the spontaneous charge transfer at the CoS1.097/Ni3S2 heterointerface induces the formation of localized electrophilic/nucleophilic regions, intelligently adsorbing electron‐donating/electron‐withdrawing groups in urea molecules, activating chemical bonds, thereby triggering urea decomposition. CoS1.097/Ni3S2 exhibits excellent catalytic activity for urea, requiring only a potential of 1.22 V (with an overpotential of 0.85 V) to achieve a current density of 100 mA cm−2 in UOR, and potentials of 1.27 and 1.57 V to reach current densities of 10 and 100 mA cm−2, respectively, in a UOR//HER electrolysis cell, maintaining good stability at high current density for 60 h. Tests in real urine have demonstrated performance similar to that in urea electrolyte. This work represents nearly the best catalytic performance of transition metal‐based materials in UOR applications, promising for both efficient hydrogen production and urea decomposition. [ABSTRACT FROM AUTHOR]

Propane dehydrogenation (PDH) is a highly efficient approach for industrial production of propylene, and the dual-atom catalysts (DACs) provide new pathways in advancing atomic catalysis for PDH with dual active sites. In this work, we have developed an efficient strategy to identify promising DACs for PDH reaction by combining high-throughput density functional theory (DFT) calculations and the machine-learning (ML) technique. By choosing the γ-Al2O3(100) surface as the substrate to anchor dual metal atoms, 435 kinds of DACs have been considered to evaluate their PDH catalytic activity. Four ML algorithms are employed to predict the PDH activity and determine the relationship between the intrinsic characteristics of DACs and the catalytic activity. The promising catalysts of CuFe, CuCo and CoZn DACs are finally screened out, which are further validated by the whole kinetic reaction calculations, and the highly efficient performance of DACs is attributed to the synergistic effects and interactions between the paired active sites. [ABSTRACT FROM AUTHOR]

The synthesis of multi-carbon (C2+) fuels via electrocatalytic reduction of CO, H2O using renewable electricity, represents a significant stride in sustainable energy storage and carbon recycling. The foremost challenge in this field is the production of extended-chain carbon compounds (Cn, n ≥ 3), wherein elevated *CO coverage (θco) and its subsequent multiple-step coupling are both critical. Notwithstanding, there exists a "seesaw" dynamic between intensifying *CO adsorption to augment θco and surmounting the C-C coupling barrier, which have not been simultaneously realized within a singular catalyst yet. Here, we introduce a facilely synthesized lattice-strain-stabilized nitrogen-doped Cu (LSN-Cu) with abundant defect sites and robust nitrogen integration. The low-coordination sites enhance θco and concurrently, the compressive strain substantially fortifies nitrogen dopants on the catalyst surface, promoting C-C coupling activity. The n-propanol formation on the LSN-Cu electrode exhibits a 54% faradaic efficiency and a 29% half-cell energy efficiency. Moreover, within a membrane electrode assembly setup, a stable n-propanol electrosynthesis over 180 h at a total current density of 300 mA cm−2 is obtained. The transformation of CO and H2O into C2+ fuels using renewable electricity represents a significant stride in carbon recycling. Here, the authors introduce a plasma-treated Cu catalyst, achieving high CO coverage and promoted C-C coupling ability for efficient n-propanol formation. [ABSTRACT FROM AUTHOR]

The advent of utilizing nitrate (NO3−) for electrochemical co‐reduction with carbon dioxide (CO2) to effectively synthesize high‐value‐added organic nitrogen compounds has captured the attention of the environmental and energy fields. C─N coupling is a key step during the electrochemical co‐reduction process. An effective strategy to improve the efficiency of synthesis is to explore the optimal reaction pathway and coupling active species. Herein, a p‐type semiconductor nanosphere (Ti‐DHTP) is presented for electrochemical co‐reduction to synthesize urea by combining CO2 and NO3−. At a low voltage of −0.6 V versus RHE, the electrochemical synthesis of urea exhibits 95.5% C‐selectivity and 21.75% Faraday efficiency. Comparative experiments, in situ experiments, and theoretical simulations confirm that a new coupling pathway for the synthesis of urea from *NH2 and *OCO intermediates become a key step in Ti‐DHTP‐driven C─N coupling. Moreover, the more efficient *OCO intermediate inhibits the generation of large amounts of C‐bearing by‐products. Meanwhile, Ti‐DHTP has difficulty hydrogenating to form *COOH during the reduction of CO2 leading to the subsequent inability to produce *CO intermediates. This work reveals a new C─N coupling mechanism, which provides a feasible strategy for future research on the electrochemical synthesis of organic nitrogen‐bearing compounds. [ABSTRACT FROM AUTHOR]