Weiyi Zhang

Covalent organic frameworks (COFs) have attracted extensive attention in rechargeable lithium‐ion batteries (LIBs) due to their structural designability, well‐defined porosity, and customizable ion storage capabilities. However, the inherently poor electron transport, along with sluggish ion‐diffusion kinetics, particularly at high current density, limits the electrochemical reaction kinetics, thereby impeding the full active sites utilization. Here, an electronic microenvironment regulation strategy through chemical structural evolution is proposed to construct a novel fully‐conjugated COF (BTTP‐COF) with localized dipole polarization. This material design boosts the electron transport driving force, thereby contributing to higher electron conductivity, and also reduces ion diffusion resistance based on the fully‐conjugated framework. Benefiting from enhanced dipole polarization, which generates an additional built‐in driving force for charge separation and electron transport, BTTP‐COF achieves a higher active site availability with an accelerated reaction rate. Notably, BTTP‐COF displays a favorable specific capacity of 297 mAh g ⁻¹ (658 Wh kg ⁻¹ ) at 0.1 A g ⁻¹ , together with exceptional calendar lifespan at 20 A g ⁻¹ with an ultralow capacity fading rate of 0.0009% per cycle (>10 000 cycles). This work provides an effective example for constructing high‐rate performance COF materials by synchronously optimizing electron transport and ion diffusion through electronic microenvironment regulation.

Covalent organic frameworks (COFs) exhibit significant potential for gas separation applications, primarily due to their remarkable stability and precisely adjustable pore structures. However, creating sustainable COF-based gas separation membranes remains unachieved and is confronted with significant challenges, including high defect sensitivity, poor recyclability, high-cost and poor pressure resistance. To address these challenges, a molecular knitting strategy is applied for reconstructing long-range ordered COF nanosheets (CONs) into super-robust and nearly defect-free COF membranes using tris(2-aminoethyl)amine (TREN) as the suture. Notably, the disassembly and self-assembly of designated CONs into membranes can be achieved through thermodynamic control by solvent switching in the presence of TREN. The underlying mechanism of this thermodynamically driven molecular structure transformation is elucidated using density functional theory calculations. The COF membranes derived from dynamically knitted CONs exhibit excellent self-healing and recycling capabilities and superior ideal selectivity for gas separation. It demonstrates an ultrahigh Young’s modulus of 19.68 GPa, corresponding to an approximate 992-fold enhancement over that of original COF membranes (0.021 GPa). Ultimately, the fabricated COF membranes exhibit outstanding pressure-resistant (ΔP > 6 bar), anti-plasticizing and H₂/CO₂ selectivity (113 ~ 52), largely surpassing the Robeson upper bound.

Conventional LiFePO₄ (LFP) cathodes employing poly(vinylidene fluoride) (PVDF) as binder exhibit relatively stable cycling performance but suffer from poor ionic conductivity, limited rate capability, restricted cycling stability at high current densities, as well as environmental concerns about the high fluorine content of PVDF. Here, we introduce an anion-cluster-mediated Li⁺ hopping mechanism in a series of newly synthesized and multifunctional poly(ionic liquid) (PIL) binders that can enable high-rate performance with an accelerated Li⁺ transport by 140-200%, meanwhile reducing the fluorine content by 60%. The counteranion aggregation along the PIL backbones can attract and promote the Li⁺ migration based on comprehensive validation of nuclear magnetic resonance spectroscopy, cyclic voltammetry and molecular dynamics simulations. The optimized LFP-PIL cathodes deliver superior high-rate performance (a capacity of 100 mAh·g^-1 at 15C) and cycling stability (95.5% capacity retention after 500 cycles at 5C). Furthermore, by integrating the chemistry-informed machine learning with experimental validation, we establish a molecular structure design methodology for next-generation PIL binders. This work provides both mechanistic insight and a generalizable design framework for high-performance and sustainable lithium cathode materials.

Photoactive ionic COFs enable efficient gold recovery from e-waste through cationic trapping and light-driven in situ Au( iii ) reduction, offering a synergistic and sustainable pathway for valuable precious metal recycling.

Porous organic cages (POCs) are structurally precise molecular solids with intrinsic internal cavities, but their limited processability has hindered their integration into functional materials. These materials offer highly customizable properties and demonstrate significant application potentials across various scopes such as gas storage/separation, organocatalysis, molecular recognition, etc. However, the transformation of POCs into processable polymers has rarely been explored. Herein, we present an organic synthetic strategy for constructing POCs into linearly linked cage polymers. This approach combines the advantageous features from both POCs and polymers, resulting in polymeric POC (PolyCC3-2OH) material with excellent solubility, stability, and processability. Interestingly, the incorporation and in situ reduction of gold ions within PolyCC3-2OH lead to Au@PolyCC3-2OH encapsulated with sub-2 nm gold nanoparticles, that exhibits remarkable performance in hydrogen production via alcoholysis of ammonia borane, with a TOF value of 150 min^-1 and remarkable recyclability. Moreover, the spin-coated PAN-PolyCC3-2OH membrane achieved >99% rejection of Coomassie Brilliant Blue and Congo Red while maintaining exceptional stability during prolonged continuous operation during membrane separation test. These findings establish PolyPOCs as a versatile molecular-to-macroscale platform for catalysis and membrane-based separations.

Encapsulation of polymer chains into nanochannels of metal-organic frameworks (MOFs) to construct polymer-MOF hybrid materials can retain the desired properties of two disparate materials. However, the facile fabrication of such hybrids remains challenging, given the difficulty in unraveling entanglement of polymer chains and constraining them into ordered conformations. Herein, we introduce an in situ molecular weaving strategy to construct ionic polymer-MOF hybrid materials, employing shear forces and coordination interactions to untangle cationic polymer chains and guide their realignment within MOF nanochannels during framework formation. Notably, this realignment promotes uniform polymer distribution and exposes more anion-exchange sites. The resulting hybrids capture ReO₄ ^¯ (a nonradioactive surrogate of ⁹⁹TcO₄ ^¯) with a capacity of 438 mg g^-1 and reach adsorption equilibrium within 20 min. Characterization and theoretical calculations reveal that the hydrophobic pores in the hybrid materials confer strong affinity toward less hydrated ⁹⁹TcO₄ ^¯ anions, thereby enhancing their selectivity over competing anions.

Gold, often recognized as a luxury jewelry, plays an important role in diverse fields because of its specific physical and chemical properties. However, the limited supply and lack of abundance of gold led to continuous competition for its use. Therefore, industries have developed various techniques for gold mining and recycling, e.g., gold recovery from electronic waste (e‐waste, commonly referred to as the gold bonanza). To address this challenge, a novel poly(ionic liquid)@covalent organic framework (PIL@COF) nanotrap for highly efficient gold recovery from e‐waste is reported. The orderly arrangement of PIL facilitated by COF nanochannels, coupled with the strong binding affinity of PIL to gold (generated by its polycarbene intermediate) and the highly ordered porous COF architecture results in the rapid and selective capture of gold ions. This polycarbene@COF material achieves a gold adsorption capacity of up to 1.9 g g ⁻¹ and exhibits excellent sorption kinetics of 90% gold adsorption within 10 min while simultaneously reducing Au ³ ⁺ to metallic Au ⁰ , which enables direct gold recovery and reuse. The high selectivity and efficiency of the gold recovery of this composite material are further confirmed by theoretical calculations. In addition, this polycarbene@COF nanotrap demonstrates high effectiveness across a wide pH range and maintains stability over multiple adsorption‒desorption cycles, highlighting its potential as a sustainable and robust platform for the recovery of precious metals.