Covalent organic frameworks (COFs) have emerged as an exciting new class of porous materials constructed by organic building blocks via dynamic covalent bonds. They have been extensively explored as potentially superior candidates for electrode materials, electrolytes, and separators, due to their tunable chemistry, tailorable structures, and well‐defined pores. These features enable rational design of targeted functionalities, facilitate the penetration of electrolytes, and enhance ion transport. This review provides an in‐depth summary of the recent progress in the development of COFs for diverse battery applications, including lithium‐ion, lithium–sulfur, sodium‐ion, potassium‐ion, lithium–CO2, zinc‐ion, zinc–air batteries, etc. This comprehensive synopsis pays particular attention to the structure and chemistry of COFs and novel strategies that have been implemented to improve battery performance. Additionally, current challenges, possible solutions, and potential future research directions on COFs for batteries are discussed, laying the groundwork for future advances for this exciting class of material.

Ternary Mg3(Bi,Sb)2 single crystals showing high thermoelectric performance are for the first time grown by the Mg flux method.

A key challenge of harvesting solar energy for chemical transformations is the scarcity of photocatalysts with broad activation wavelength and easily tunable band structures. Here, we introduce lead halide perovskite (CsPbBr 3 ) nanocrystals as band-edge-tunable photocatalysts for efficient photoinduced electron/energy transfer−reversible addition−fragmentation chain transfer (PET-RAFT) polymerization. PET-RAFT polymerization of various functional monomers is successfully conducted using a broad range of irradiation sources ranging from blue to red light (460 to 635 nm), resulting in polymer products with narrow dispersity (Đ = 1.02−1.13) and high degree of chain-end fidelity. Furthermore, the giant two-photon absorption cross-section of CsPbBr 3 enables activation with a light source in the near-infrared region (laser pulses centered at 800 nm) for the PET-RAFT process.

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Covalent organic frameworks (COFs) are crystalline organic materials of interest for a wide range of applications due to their porosity, tunable architecture, and precise chemistry. However, COFs are typically produced in powder form and are difficult to process. Herein, we report a simple and versatile approach to fabricate macroscopic, crystalline COF gels and aerogels. Our method involves the use of dimethyl sulfoxide as a solvent and acetic acid as a catalyst to first produce a COF gel. The COF gel is then washed, dried, and reactivated to produce a pure macroscopic, crystalline, and porous COF aerogel that does not contain any binders or additives. We tested this approach for six different imine COFs and found that the crystallinities and porosities of the COF aerogels matched those of COF powders. Electron microscopy revealed a robust hierarchical pore structure, and we found that the COF aerogels could be used as absorbents in oil–water separations, for the removal of organic and inorganic micropollutants, and for the capture and retention of iodine. This study provides a versatile and simple approach for the fabrication of COF aerogels and will provide novel routes for incorporating COFs in applications that require macroscopic, porous materials.

Light-mediated radical polymerization has benefited from the rapid development of photoredox catalysts and offers many exceptional advantages over traditional thermal polymerizations. Nevertheless, the majority of the work relies on molecular photoredox catalysts or expensive transition metals. We exploited the capability of semiconductor quantum dots (QD) as a new type of catalyst for the radical polymerization that can harness natural sunlight. Polymerizations of (meth)­acrylates, styrene, and construction of block copolymers were demonstrated, together with temporal control of the polymerization by the light source. Photoluminescence experiments revealed that the reduction of alkyl bromide initiator by photoexcited QD is the key to this light-mediated radical polymerization.

Porphyrin-based donor–acceptor COFs are effective heterogeneous photocatalysts for photoinduced electron transfer-reversible addition–fragmentation chain transfer (PET-RAFT), including for aqueous polymerizations and under red-light excitation.

HIGHLIGHTS • 0D-2D SnO 2 quantum dots/MXene (SnO 2 QDs/MXene) hybrids were synthesized by electrostatic self-assembly. • MXene not only provides efficient pathways for fast transport of electrons and Li ions, but also buffers the volume change of SnO 2 during charge/discharge process. • The 0D-2D SnO 2 QDs/MXene hybrids deliver high capacity, excellent cycle and rate performances as anode of lithium-ion batteries. ABSTRACT MXenes, a new family of two-dimensional (2D) materials with excellent electronic conductivity and hydrophilicity, have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes. Herein, a facile electrostatic self-assembly of SnO 2 quantum dots (QDs) on Ti 3 C 2 T x MXene sheets is proposed. The as-prepared SnO 2 /MXene hybrids have a unique 0D-2D structure, in which the 0D SnO 2 QDs (~ 4.7 nm) are uniformly distributed over 2D Ti 3 C 2 T x MXene sheets with controllable loading amount. The SnO 2 QDs serve as a high capacity provider and the "spacer" to prevent the MXene sheets from restacking; the highly conductive Ti 3 C 2 T x MXene can not only provide efficient pathways for fast transport of electrons and Li ions, but also buffer the volume change of SnO 2 during lithiation/delithiation by confining SnO 2 QDs between the MXene nanosheets. Therefore, the 0D-2D SnO 2 QDs/MXene hybrids deliver superior lithium storage properties with high capacity (887.4 mAh g −1 at 50 mA g −1), stable cycle performance (659.8 mAh g −1 at 100 mA g −1 after 100 cycles with a capacity retention of 91%) and excellent rate performance (364 mAh g −1 at 3 A g −1), making it a promising anode material for lithium-ion batteries.