Copper-based catalysts are the choice for producing multi-carbon products (C2+) during CO2 electroreduction (CO2RR), where the Cu0Cuδ+ pair sites are proposed to be synergistic hotspots for C-C coupling. Maintaining their dynamic stability requires precise control over electron affinity and anion vacancy formation energy, posing significant challenges. Here, we present an in-situ reconstruction strategy to create dynamically stable Cu0Cu0.
View Article and Find Full Text PDFPhotothermal catalysis is an emerging field with significant potential for sustainable chemical production processes. The merger of single-atom catalysts (SACs) and photothermal catalysis has garnered widespread attention for its ability to achieve precise bond activation and superior catalytic performance. This review provides a comprehensive overview of the recent progress of SACs in photothermal catalysis, focusing on their underlying mechanisms and applications.
View Article and Find Full Text PDFAchieving efficient and stable hydrogen evolution reactions in alkaline conditions is crucial for hydrogen production. In this study, a RuIr/CoNC-P catalyst featuring RuIr alloys alongside P-doping and CoNx sites is developed. RuIr alloying optimizes the electronic structure between Ru and Ir, promoting electron transfer from Ru to Ir.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2024
Lithium-sulfur (Li-S) batteries exhibit great potential as the next-generation energy storage techniques. Application of catalyst is widely adopted to accelerate the redox kinetics of polysulfide conversion reactions and improve battery performance. Although significant attention has been devoted to seeking new catalysts, the problem of catalyst passivation remains underexplored.
View Article and Find Full Text PDFBackground: Traditional Chinese medicine formulations often contain hydrophobic components with limited solubility and stability, leading to low oral bioavailability. Self-assembled nanoparticles (SANs) have shown promise in enhancing oral bioavailability of these components. However, whether un-decocted Chinese herbal pellets can generate SANs and the impact of SANs formed by multiple components on pharmacokinetic parameters remains unexplored.
View Article and Find Full Text PDFMetal-catalyzed semi-hydrogenation of alkynes is an important step in organic synthesis to produce diverse chemical compounds. However, conventional noble metal catalysts often suffer from poor selectivity owing to over-hydrogenation. Here, we demonstrate a high-loading bimetallic AgCu-CN single-atom catalyst (SAC) for alkyne semi-hydrogenation.
View Article and Find Full Text PDFFree radicals, generally formed through the cleavage of covalent electron-pair bonds, play an important role in diverse fields ranging from synthetic chemistry to spintronics and nonlinear optics. However, the characterization and regulation of the radical state at a single-molecule level face formidable challenges. Here we present the detection and sophisticated tuning of the open-shell character of individual diradicals with a donor-acceptor structure via a sensitive single-molecule electrical approach.
View Article and Find Full Text PDFPeople have been looking for an energy-efficient and sustainable method to produce future chemicals for decades. Heterogeneous single-atom catalysts (SACs) with atomic dispersion of robust, well-characterized active centers are highly desirable. In particular, correlated SACs with cooperative interaction between adjacent single atoms allow the switching of the single-site pathway to the dual or multisite pathway, thus promoting bimolecular or more complex reactions for the synthesis of fine chemicals.
View Article and Find Full Text PDFThe dynamic response of single-atom catalysts to a reactive environment is an increasingly significant topic for understanding the reaction mechanism at the molecular level. In particular, single atoms may experience dynamic aggregation into clusters or nanoparticles driven by thermodynamic or kinetic factors. Herein, the inherent mechanistic nuances that determine the dynamic profile during the reaction will be uncovered, including the intrinsic stability and site-migration barrier of single atoms, external stimuli (temperature, voltage, and adsorbates), and the influence of catalyst support.
View Article and Find Full Text PDFObjective To investigate the expression and clinical significance of PD-1 and its ligand PD-L1 in peripheral blood CD19CD25 regulatory B cells (Bregs) in patients with systemic lupus erythematosus (SLE). Methods Peripheral blood samples were collected from 50 patients and 41 healthy controls (HCs). The proportion of CD19CD25Bregs in peripheral blood as well as the expression of PD-1B and PD-L1B cells on CD19CD25B cells, were detected by flow cytometry.
View Article and Find Full Text PDFElectrochemical synthesis of ammonia via the nitrate reduction reaction (NO3RR) has been intensively researched as an alternative to the traditional Haber-Bosch process. Most research focuses on the low concentration range representative of the nitrate level in wastewater, leaving the high concentration range, which exists in nuclear and fertilizer wastes, unexplored. The use of a concentrated electrolyte (≥1 M) for higher rate production is hampered by poor hydrogen transfer kinetics.
View Article and Find Full Text PDFBackground: The defect of B cell self-tolerance and the continuous antigen presentation by T cells (TCs) mediated by autoreactive B cells (BCs) play a key role in the occurrence and development of systemic lupus erythematosus (SLE). PD-1/PD-L1 signaling axis negatively regulates the immune response of TCs after activation and maintains immune tolerance. However, the effect of PD-1/PD-L1 signaling axis on the interaction between CD19B/CD4TCs in the peripheral blood of patients with SLE has not been studied in detail.
View Article and Find Full Text PDFWe report a rationally designed membrane-intercalating conjugated oligoelectrolyte (COE), namely COE-IC, which endows aerobic N -fixing bacteria Azotobacter vinelandii with a light-harvesting ability that enables photosynthetic ammonia production. COE-IC possesses an acceptor-donor-acceptor (A-D-A) type conjugated core, which promotes visible light absorption with a high molar extinction coefficient. Furthermore, COE-IC spontaneously associates with A.
View Article and Find Full Text PDFThe zinc oxide (ZnO) nanoparticles (NPs) are well-documented as an excellent electron transport layer (ETL) in optoelectronic devices. However, the intrinsic surface flaw of the ZnO NPs can easily result in serious surface recombination of carriers. Exploring effective passivation methods of ZnO NPs is essential to maximize the device's performance.
View Article and Find Full Text PDFDynamic reconstruction of catalyst active sites is particularly important for metal oxide-catalyzed oxygen evolution reaction (OER). However, the mechanism of how vacancy-induced reconstruction aids OER remains ambiguous. Here, we use CoO with Co or O vacancies to uncover the effects of different defects in the reconstruction process and the active motifs relevant to alkaline OER.
View Article and Find Full Text PDFSingle-atom catalysts (SACs) show great potential for rechargeable Zn-air batteries (ZABs); however, scalable production of SACs from sustainable resources is difficult owing to poor control of the local coordination environment. Herein, lignosulfonate, a by-product of the papermaking industry, is utilized as a multifunctional bioligand for the mass production of SACs with highly active MN S sites (M represents Fe, Cu, and Co) via strong metalnitrogen/sulfur coordination. This effectively adjusts the charge distribution and promotes the catalytic performance, leading to highly durable and excellent performance in oxygen reduction and evolution reactions for ZABs.
View Article and Find Full Text PDFTo realize the practical application of lithium-sulfur (Li-S) batteries, there is a need to inhibit uncontrolled Li deposition by facilitating Li-ion migration, and suppress the irreversible consumption of cathodes by preventing polysulfide shuttling. However, a permselective artifical membrane or interlayer which features fast ion transport but low polysulfide crossover is elusive. Here, we report the design and synthesis of a fluorinated covalent organic framework (4F-COF)-based membrane with a high permselectivity and increased battery lifespan.
View Article and Find Full Text PDFReducing particle size in supported metal catalysts to single-atom level isolates the active metal sites and maximizes the atomic utilization efficiency. However, the large inter-atom distance, particularly in low-loading single-atom catalyst (SAC), is not favorable for a complex reaction where two (or more) reactants have to be activated. A key question is how to control the inter-atom distances to promote dinuclear-type coactivation at the adjacent metal sites.
View Article and Find Full Text PDFSingle-atom catalysts (SACs) offer many advantages, such as atom economy and high chemoselectivity; however, their practical application in liquid-phase heterogeneous catalysis is hampered by the productivity bottleneck as well as catalyst leaching. Flow chemistry is a well-established method to increase the conversion rate of catalytic processes, however, SAC-catalysed flow chemistry in packed-bed type flow reactor is disadvantaged by low turnover number and poor stability. In this study, we demonstrate the use of fuel cell-type flow stacks enabled exceptionally high quantitative conversion in single atom-catalyzed reactions, as exemplified by the use of Pt SAC-on-MoS/graphite felt catalysts incorporated in flow cell.
View Article and Find Full Text PDFMost organic semiconductors have closed-shell electronic structures, however, studies have revealed open-shell character emanating from design paradigms such as narrowing the bandgap and controlling the quinoidal-aromatic resonance of the π-system. A fundamental challenge is understanding and identifying the molecular and electronic basis for the transition from a closed- to open-shell electronic structure and connecting the physicochemical properties with (opto)electronic functionality. Here, we report donor-acceptor organic semiconductors comprised of diketopyrrolopyrrole and naphthobisthiadiazole acceptors and various electron-rich donors commonly utilized in constructing high-performance organic semiconductors.
View Article and Find Full Text PDFNarrow bandgap donor-acceptor organic semiconductors are generally considered to show a closed-shell singlet ground state, and their radicals are reported as impurities, defects, polarons, and charge transfer monoradicals. Herein, we systematically investigated the open-shell singlet diradical electronic ground state of two diketopyrrolopyrrole-based compounds via the combination of electron spin resonance (ESR), nuclear magnetic resonance, superconducting quantum interference device magnetometry, and theoretical calculations. It is widely known that the quinoidal character will be significantly enhanced in the aggregation state accompanied by improved planarity and enhanced delocalization.
View Article and Find Full Text PDFThe uncontrollable dendrite growth of Li metal anode leads to poor cycle stability and safety concerns, hindering its utilization in high energy density batteries. Herein, a phenoxy radical Spiro-O8 is proposed as an artificial protection film for Li metal anode owing to its excellent film-forming capability and remarkable ionic conductivity. A spontaneous redox reaction between the Spiro-O8 and Li metal results in the formation of a uniform and highly ionic conductive organic film in the bottom.
View Article and Find Full Text PDFDue to the unfavorable soil conditions and water resources, the cropland use pattern in the farming-pastoral ecotone in northern China is complex. The program named "Grain for Green" has accelerated the cropland change. However, the complex cropland and retired cropland are challenging to monitor with remote sensing due to their spatially dispersed and easily confused with spectrally similar land use classes such as nature grasslands and non-cropped fields.
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