The ordered modular structure of a covalent organic framework (COF) facilitates the selective incorporation of electronically active segments that can be tuned to function cooperatively. This designability inspires developing COFbased single-source white light emitters, required in nextgeneration solid-state lighting. Here, we present a new anthracene-resorcinol-based COF exhibiting white light emission. The keto−enol tautomers present in the COF give rise to dual emission, which can be tuned by the O-donor and Ndonor solvents. Importantly, when suspended in a solid polymer matrix, this dual emission is retained as both tautomers coexist. A mere 0.32 wt % loading of the COF in poly(methyl methacrylate) (PMMA) gives a solvent-free film with intense white light emission (CIE coordinates (0.35, 0.36)). From steady-state and time-resolved studies, the mechanism of the white light emission has been unambiguously assigned to fluorescence, with the blue emission originating from the π-stacked columns of anthracene, and the mixture of red and green from the keto−enol tautomerized resorcinol units. The study introduces the COF as a new class of readily processable, single-source white light emitter.

A covalent organic framework (COF), built from light atoms with a graphitic structure, could be an excellent anodic candidate for lightweight batteries, which can be of use in portable devices. But to replace the commercial graphite anode, they need more Li‐interactive sites/unit‐cell and all such sites should be made to participate. The compromise made in the volumetric density to gain the gravimetric advantage should be minimal. Exfoliation enhances surface/functional group accessibility yielding high capacity and rapid charge storage. A chemical strategy for simultaneous exfoliation and increase of Li‐loving active‐pockets can deliver a lightweight Li‐ion battery (LIB). Here, anthracene‐based COFs are chemically exfoliated into few‐layer‐thick nanosheets using maleic anhydride as a functionalizing exfoliation agent. It not only exfoliates but also introduces multiple Li‐interactive carbonyl groups, leading to a loading of 30 Li/unit‐cell (vs one Li per C6). The exfoliation enhances the specific capacity by ≈4 times (200–790 mAh g−1 @100 mA g−1). A realistic full‐cell, made using the exfoliated COF against a LiCoO2 cathode, delivers a specific capacity of 220 mAh g−1 over 200 cycles. The observed capacity stands highest among all organic polymers. For the first report of a COF derived full‐cell LIB, this is a windfall.

Covalent organic frameworks (COFs), because of their ordered pores and crystalline structure, become designable polymers for charge storage applications. Supercapacitors are critical in developing hybrid energy devices. Amalgamating these high-surface-area frameworks in the capacitor assembly can aid develop robust solid-state supercapacitors. Here, we present supercapacitors drawn on three closely related pyridyl-hydroxyl functionalized COFs. The keto-enol tautomerism and the hydrogen bonding ability of the hydroxyl units promise added chemical stability in this potentially hydrolyzable Schiff-bonded COF. Meanwhile, the pyridyl and triazine groups ensure rapid charge storage by reversibly interacting with protons from the acidic electrolyte. The COF with the highest surface area, as expected, yields an excellent specific capacitance of 546 F/g at 500 mA/g in acidic solution and ∼92 mF/cm2 at 0.5 mA/cm2 in the solid-state device, which is the highest among all the COF-derived solid-state capacitors, which is reflected by a high power density of 98 μW/cm2 at 0.5 mA/cm2, most of which is retained even after 10 000 cycles. This high activity comes from a smooth electrical-double-layer-capacitance favored by an ordered-porous structure and some pseudo-capacitance assisted by the participation of redox-active functional groups. The study highlights the by-design development of COFs for superior energy/charge devices.

Covalento rganic frameworks are an ew class of crystalline organic polymers possessing ah igh surfacea rea and ordered pores. Judicious selection of buildingb locks leads to strategic heteroatom inclusion into the COF structure. Owing to their high surfacea rea, exceptional stability and molecular tunability,C OFs are adopted for various potential applications. The heteroatoms lining in the pores of COF favor synergistich ost-guest interaction to enhance a targeted property.I nt his report, we have synthesized ar esorcinol-phenylenediamine-based COF which selectively adsorbs CO 2 into its micropores (12 ). The heat of adsorption value (32 kJ mol À1 )o btainedf rom the virial model at zero-loading of CO 2 indicates its favorable interaction with the framework. Furthermore, we have anchored small-sized Ag nanoparticles ( % 4-5 nm) on the COF and used the composite for chemicalf ixationo fC O 2 to alkylidenec yclic carbonates by reacting with propargyl alcohols under ambient conditions. Ag@COFc atalyzes the reaction selectively with an excellent yield of 90 %. Recyclability of the catalyst has been demonstrated up to five consecutivec ycles. The postcatalysis characterizations revealt he integrity of the catalyst even after fiver eaction cycles.T his study emphasizes the ability of COF for simultaneous adsorption and chemical fixation of CO 2 into corresponding cyclic carbonates.

Capacitors are the most practical high‐storage and rapid charge‐release devices. The number of ions stored per unit area and their interaction strength with the electrode dictates capacitor‐performance. Microporous materials provide a high storage surface and optimal interactions. Adsorbing electron‐rich and easily polarizable molecules into microporous electrodes is expected to boost Faradaic pseudo‐activity. If such electrode–electrolyte interactions can be made as a potential‐driven reversible process, the resulting capacitors would be adaptable and device‐friendly. A composite covalent organic framework (COF)‐carbon electrode with redox‐active KI is combined in an H2SO4 electrolyte for the first time. This composite electrode benefits from the redox‐functionality of COF and electronic conductivity of carbon, leading to superior capacitative activity. Operando spectro‐electrochemical measurements reveal the existence of multiple polyiodide species, although the I3− is the predominantly electroactive species adsorbing on the microporous triazine‐phenol COF electrode. A systematic fabrication of the flexible solid‐state devices using the COF‐redox‐electrolyte reveals a high areal capacitance of 270 ± 11 mF cm−2 and gravimetric capacitance of 57 ± 8 F g−1. The inclusion of KI in H2SO4 (electrolyte) yields an approximately eight‐fold enhancement in solid‐state gravimetric specific capacitance. The imine‐COF retains 89% of its capacity even after 10 000 cycles.

Exceptionally stable ultramicroporous C–C-bonded porous organic frameworks (IISERP-POF6, 7, 8) have been prepared using simple Friedel–Crafts reaction. These polymers exhibit permanent porosity with a Brunauer–Emmett–Teller surface area of 645–800 m2/g. Xe/Kr adsorptive separation has been carried out with these polymers, and they display selective Xe capture (s(Xe/Kr) = 6.7, 6.3, and 6.3) at 298 K and 1 bar pressure. Interestingly, these polymers also show remarkable Xe/N2 (s(Xe/N2) = 200, 180, and 160 at 298 K and 1 bar) and Xe/CO2 selectivity (s(Xe/CO2) = 5.6, 7.4, and 5.6) for a 1:99 composition of Xe–N2/Xe–CO2. Selective removal of Xe at such low concentrations is extremely challenging; the observed selectivities are higher compared to those observed in porous carbons and metal–organic frameworks. Breakthrough studies were performed using the composition relevant to the nuclear off-gas mixture with the polymers, and we find that the polymers hold Xe for a longer time in the column, which illustrates the Xe/Kr separation performance under dynamic conditions.

Covalent organic frameworks (COFs) made of light atoms such as H, C, N, and O with a significant void-to-framework ratio are excellent low-density supports for nanoparticles (nPs). Their framework can be precoded with heteroatoms to ensure binding with metallic nanoclusters. With these advantages, if controlled amounts of magnetic nPs are anchored to them, they can yield low-density organic−inorganic nanomagnets. Their organic nature facilitates fusion with bulk materials such as paper/textile to enable bulk composites with well-dispersed lowdensity magnets, which have potential for defense and nextgeneration aviation applications. Herein, we have grown small Fe/ Fe 3 O 4 nPs (5−18 wt %) inside a COF. Interestingly, 300 mg of this organic−inorganic framework material (containing 50 mg of nPs) can lift a vial of ∼15,000 mg (300 times heavier). Also, the hydrophobic COF wraps around the Fe/Fe 3 O 4 nanocluster retaining its room-temperature magnetic character even after 1 year, while the naked nPs lose it within a few days because of air oxidation. Bulk composites with paper and polymers have been made using this low-density Fe−COF to demonstrate their processability.

Developing stable active catalysts for reducing water-soluble pollutants is a desirable target. In this pursuit, we have functionalized covalent organic frameworks (COFs) with gold (Au) and cobalt (Co) nanoparticles via a one-step aqueous synthesis process, and their catalytic activity in reducing methyl orange and methylene blue is examined. Operando absorbance measurements of methyl orange (anionic dye) reduction revealed AuCoCOF (1.3 Au/1.0 Co) to have superior kinetics over many other catalysts, which typically require additional external stimuli (e.g., photons) and higher catalyst loadings. After confirming the homogeneous dispersion of the nanoparticles on the COF support using three-dimensional (3D) tomography and material stability through powder X-ray diffraction (PXRD), infrared (IR), and thermal studies, we investigated their redox activity. Cyclic voltammetry (CV) confirmed the involvement of both metals in the redox process, while spectroelectrochemical measurements show that their activity and kinetics remain unaltered by an applied potential. Solid-state UV measurements reveal that the neat COF is a semiconductor with a large band gap (2.8 eV), which is substantially lowered when loaded with cobalt nanoparticles (2.2 eV for CoCOF). The electronic synergy between Au and Co nanoparticles further reduces the band gap of AuCoCOF (1.9 eV). Thus, there is a definite advantage in doping non-noble metal nanoparticles into a noble metal lattice and nanoconfining them into a porous COF support. Our study highlights the significance of bimetallic COF-supported nanocatalysts, wherein one can engage each component toward targeted applications that demand redox activity with favorable kinetics.