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In this study, we synthesized two new two-dimensional (2D) covalent organic frameworks (COFs), COF-TA and COF-DP, by combining 4-connected D2h-symmetric and 2-connected non-centrosymmetric C2-symmetric building blocks. Unlike the typical sql topology, these COFs exhibit an unconventional kgm topology characterized by a favorable anti-parallel stacking arrangement, which results in a lower energy configuration. Notably, COF-DP, with its unique D–A–D structural motif and photosensitive properties, demonstrates a narrow band gap and excellent photothermal conversion capabilities, making it a promising material for photothermal imaging applications. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) have attracted intensive attention as promising next-generation energy storage systems, due to the high energy density and low cost of sulfur cathodes. Despite the substantial progress in improving LSBs' performance, their wide implementation still suffers from great challenges, including the difficulties in achieving practically high energy density with long cycle life and the concerns about the limited lithium resources. The former issue mainly arises from the insufficient understanding of the mechanics of the complex lithium–sulfur redox reactions, while the latter trigger the exploration of a range of new metal–sulfur systems, such as sodium–sulfur, potassium–sulfur, magnesium–sulfur, calcium–sulfur, and aluminum–sulfur batteries. These lithium-free metal–sulfur batteries (MSBs) have the potential to offer higher energy density or/and lower battery costs. The fundamental understanding and rational regulation of effective metal–sulfur conversion reactions are crucial for developing advanced and emerging MSBs. Herein, this work aims to overview the state-of-the-art progress in circumventing these issues of MSBs, in terms of working mechanisms, key factors determining the electrochemical behavior and battery performance. Advanced in situ characterization techniques used to disclose the sulfur conversion mechanisms are also elaborately discussed. Conclusions and perspectives for the future research direction in MSBs are proposed. [ABSTRACT FROM AUTHOR]

A novel single-solvent-interfacial strategy is proposed to synthesize hollow MOFs, fabricated at the two-phase interface originated from the self-deliquescence of hydration water in the metallic precursors and the solvents with low water solubility. The as-fabricated HMOFs with hierarchically porous structures exhibit significant enhancement in CO2 separation and catalysis. [ABSTRACT FROM AUTHOR]

Calcium (Ca)-based rechargeable batteries (CRBs) have been considered one of the most promising post-lithium ion battery technologies because of the natural abundance of Ca, high volumetric capacity compared to monovalent metal batteries, and the low reduction potential of Ca2+/Ca. Recently, a breakthrough of Ca reversible plating and stripping at the Ca metal anode in carbonate electrolytes has induced the study of Ca rechargeable batteries. This critical review presents the state-of-the-art progress made in exploring potential electrode materials including Ca metal anodes, alternative graphite and alloy-type anodes, and cathode materials undergoing interaction or conversion reactions. Suitable electrolytes are also required to ensure the compatibility of each cell component, which is essential toward high-performance Ca full batteries. The performance assessment and mechanism analysis are further discussed to evaluate the current progress and existing challenges regarding the performance promise and insufficient understanding of the Ca battery technology. To conclude, this review provides a comprehensive understanding of the underlying mechanisms and challenges that need to be addressed to promote the commercialization of CRBs. [ABSTRACT FROM AUTHOR]

On the way to exploring superior hydrogenation catalysts, Ir-based catalysts with a record catalytic activity (up to 40 h−1) for the hydrogenation of benzoic acid to cyclohexanecarboxylic acid under mild reaction conditions (85 °C, 0.1 MPa H2, in water) have been successfully developed. By excluding various factors, the experimental results showed that the main factor governing the activity discrepancy between the Ir-based catalysts is actually the dispersion stability of the supports (such as N-doped carbon, active carbon, SBA-15 and various metal oxides) in the reaction solution, rather than the interaction between the Ir active component and the supports. Combined with theoretical investigation from first principles, an activity volcano curve considering the competing adsorption between the reactants (H2) and solvent (H2O) for aqueous aromatic ring hydrogenation was presented for the first time. The high activity of Ir can be deduced by the proper discrepancy of dissociation energies or adsorption energies between H2 and H2O on the catalysts. This activity volcano curve provides guidance for further rational design of promising catalysts for benzoic acid or even aromatic ring hydrogenation under true reaction conditions for practical applications. [ABSTRACT FROM AUTHOR]

In this study, we synthesized two new two-dimensional (2D) covalent organic frameworks (COFs), COF-TA and COF-DP, by combining 4-connected D 2h -symmetric and 2-connected non-centrosymmetric C 2 -symmetric building blocks. Unlike the typical sql topology, these COFs exhibit an unconventional kgm topology characterized by a favorable anti-parallel stacking arrangement, which results in a lower energy configuration. Notably, COF-DP, with its unique D-A-D structural motif and photosensitive properties, demonstrates a narrow band gap and excellent photothermal conversion capabilities, making it a promising material for photothermal imaging applications.

A novel single-solvent-interfacial strategy is proposed to synthesize hollow MOFs, fabricated at the two-phase interface originated from the self-deliquescence of hydration water in the metallic precursors and the solvents with low water solubility. The as-fabricated HMOFs with hierarchically porous structures exhibit significant enhancement in CO 2 separation and catalysis.