Abstract

Seawater electrolysis holds great promise for hydrogen production in the future, while the development of anodic catalysts has been severely hampered by the side-reaction, chloride evolution reaction. In this work, nano-flower-cluster structured CoO@FeSe₂/CF catalysts are synthesized via a scalable electrodeposition technique, and the performance is systematically studied. The oxygen evolution reaction (OER) overpotential of CoO@FeSe₂/CF is 267 mV at 100 mA cm⁻², which is significantly lower than the IrO₂ catalyst (435 mV). Additionally, the catalyst shows high selectivity for OER (97.9%) and almost no loss of activity after a durability test for 1100 h. The impressive performance is attributed to the dense rod-like structure with abundant active centers after electrochemical activation and the in-situ generated CoOOH and FeOOH that improves the catalytic activity of the catalyst. The synergistic effect induced by the non-uniform structure endows the catalyst with excellent stability.

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Comprehensive Summary

As the third generation new battery, the power conversion efficiency (PCE) of metal halide perovskite solar cells (PSCs) has increased from 3.8% in 2009 to 25.8% currently certified, which fully shows that they have great research value and development prospect. As one of the main components of high-efficiency PSCs, hole transport materials (HTMs) play an important role in extracting and transporting holes and inhibiting charge recombination. However, commonly used HTMs require doping, and the hygroscopicity and corrosiveness of the dopants will destroy the stability of PSCs and hinder their commercialization. Therefore, it is of great significance to develop dopant-free HTMs. In this review, the dopant-free HTMs in recent six years are reviewed and summarized systematically, including organic small molecules, polymers and cross-linkable materials. We focus on the design of the molecular cores and discuss their structure–property correlation, conductivity, and photovoltaic performance. Finally, how to design an ideal HTM is summarized. We hope that this review can provide reference for the development of low-cost and dopant-free HTMs to prepare efficient and stable PSCs.

Comprehensive Summary

This review covers the isolation, structural determination, plausible biosynthetic pathways, and biological activities of 166 natural terpenoids including 57 sesquiterpenoids, 65 diterpenoids, 15 sesterterpenoids, and 29 triterpenoids from January 2017 to December 2022.

We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates. This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials, generates CO₂ as the only byproduct, and features broad substrate scopes with good functional group compatibility.

Comprehensive Summary

We describe an iron-catalyzed amide bond formation from readily available carboxylic acids and isocyanates. This method utilizes an abundant and biocompatible iron catalyst and easily accessible starting materials, generates CO₂ as the only byproduct, and features broad substrate scopes with good functional group compatibility. Therefore, it provides a cost-effective and practical protocol to access a diverse variety of amides.

Ligand-protected gold (Au_n) clusters sometimes need the removal of organic ligands to expose more active sites and reduce steric hindrance in catalytic reactions, and large amount of organic and inorganic materials usually need to be employed as supports to anchor Au_n clusters through different interaction mechanisms. Whereas, less comprehensive summaries have been provided about the crucial contribution of various supports on the catalytic performance of the supported Au_n clusters. Herein, this review firstly summarizes synthesis methods (e.g., impregnation and encapsulation processes) for the supported Au_n cluster catalysts, and then mainly points out specific contributions of support effect in a great diversity of catalytic reactions, as well as deep interaction mechanisms. Besides, opportunities and challenging issues will be stated towards supported Au_n clusters, in terms of improving catalytic performance and structural stability of Au_n clusters in the demand of catalysis.

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Abstract

Adhesive hydrogels are an emerging class of hydrogels that combine three-dimensional hydrated networks with adhesive properties. These properties facilitate intimate tissue-material contact in diverse biomedical applications, enhancing tissue joining, drug transport, and signal transmission. Inspired by the universal adhesiveness of mussel foot proteins, 3,4-dihydroxyphenyl-L-alanine (DOPA) and its analogs have been extensively exploited for the fabrication of adhesive hydrogels, within which the DOPA moieties can not only serve as cross-linking mediators but also participate in various intermolecular and surface interactions to mediate wet adhesion. This mini-review highlights recent achievements in the development of mussel-inspired adhesive hydrogels, focusing on: (1) elucidating DOPA-mediated adhesion mechanisms through nanomechanical characterizations, (2) designing injectable adhesive hydrogels toward applications in drug delivery, hemostasis, and wound closure, which includes in situ gelling liquids and shear-thinning preformed hydrogels, and (3) fabricating tough adhesive hydrogels with enhanced mechanical properties for use in tissue regeneration, biosensing, and bioimaging, with typical examples of nanocomposite and double-network hydrogels. The challenges and prospects in this rapidly developing field are also discussed.

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A facile and efficient DMAP-catalyzed [4+2] annulation of allenoates with arylazosulfones is developed for the synthesis of tetrahydropyridazine derivatives under mild and metal-free conditions, and this tandem cycloaddition exhibits high functional group tolerance and easy manipulation. In addition, the tetrahydropyridazine derivatives can be transformed into pyridazin-3-one derivatives in the presence of DDQ.

Comprehensive Summary

Herein, a DMAP-catalyzed [4+2] annulation of α-substituted allenoates with arylazosulfones is reported, which affords facile access to tetrahydropyridazine derivative in synthetically useful yields. This reaction features mild conditions and good functional group tolerance. Moreover, the resultant products can be readily transformed into pyridazin-3-one derivatives in the presence of DDQ.

A polymer acceptor PNT with expanded CPNM end groups was developed, which exhibited the increased molecular rigidity and broaden absorption spectrum. And the all-PSCs achieved a power conversion efficiency of 13.7% with a high short-circuit current density (J _SC = 24.4 mA·cm⁻²).

Comprehensive Summary

Narrow-bandgap n-type polymers are essential for advancing the development of all-polymer solar cells (all-PSCs). Herein, we developed a novel polymer acceptor PNT with π-extended 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene) malononitrile (CPNM) end groups. Compared to commonly used 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1ylidene) malononitrile (IC) units, CPNM units have a further extended fused ring, providing the PNT polymer with extended absorption into the near-IR region (903 nm) and exhibiting a narrow optical bandgap (1.37 eV). Furthermore, PNT exhibits a high electron mobility (6.79 × 10⁻⁴ cm²·V⁻¹·S⁻¹) and a relatively high-lying lowest unoccupied molecular orbital (LUMO) energy level of −3.80 eV. When blended with PBDB-T, all-PSC achieves a power conversion efficiency (PCE) of 13.7% and a high short-circuit current density (J _SC) of 24.4 mA·cm⁻², mainly attributed to broad absorption (600—900 nm) and efficient charge separation and collection. Our study provides a promising polymer acceptor for all-PSCs and demonstrates that π-extended CPNM units are important to achieve high-performance for all-PSCs.

Cobalt/photoredox dual-catalyzed asymmetric reductive Grignard-type addition of aryl iodides with axially prochiral biaryl dialdehydes was developed, leading to the direct construction of axially chiral secondary alcohols in good yields with high stereoselectivity, enabled by desymmetrization followed by efficient kinetic recognition of diastereomers and kinetic resolution.

Comprehensive Summary

Secondary alcohols bearing both axial and central chirality comprise attractive biological activity and exhibit excellent chiral induction in asymmetric reactions. However, only very limited asymmetric catalytic approaches were developed for their synthesis. We herein describe visible light-mediated cobalt-catalyzed asymmetric reductive Grignard-type addition of aryl iodides with axially prochiral biaryl dialdehydes leading to the direct construction of axially chiral secondary alcohols. Preliminary mechanistic studies indicate that efficient kinetic recognition of diastereomers might occur for axially prochiral dialdehydes to improve the stereoselectivity, which might open a new avenue for the challenging cascade construction of multiple chiral elements. This protocol features excellent enantio- and diastereoselectivity, green and mild conditions, simple operation, and broad substrate scope, providing a modular platform for the synthesis of secondary axially chiral alcohols.

Comprehensive Summary

Here, we combined the photon antibunching analysis, fluorescence correlation spectroscopy, and time-domain fluorescence lifetime imaging microscopy (TD-FLIM) to study the emission properties of a representative AIE-luminogen—4,4’-(benzo[c][1,2,5] thiadiazole-4,7-diyl)bis(N,N-diphenylaniline) (TPA-BT) at the single emitter level in a tetrahydrofuran (THF)/water solution where water is a non-solvent for TPA-BT. Our findings suggest that, at a constant water fraction in the solution, the size of TPA-BT aggregates increases with the TPA-BT concentration; TPA-BT aggregates are not a quantum emitter at room temperature in the solution. Moreover, utilizing TD-FLIM and a gel trapping technique allowed us to study the fluorescence lifetime of individual TPA-BT aggregates. Adding a polar solvent like water does not result in an overall decrease in fluorescence lifetime. Rather, it causes the fluorescence lifetime distribution to become wider, and only some molecules experience a decrease in their fluorescence lifetime. These results could represent a step forward in further understanding the photophysics of AIE-luminogens.