02312nas a2200241 4500008004100000022001400041245012600055210006900181260000800250520143000258653001601688653003201704653002201736653002301758653002501781100002601806700002201832700002201854700002001876700001801896700003001914856012601944 2019 eng d a1861-472800aAg nanoparticles supported on a resorcinol-phenylenediamine-based covalent organic framework for chemical fixation of CO20 aAg nanoparticles supported on a resorcinolphenylenediaminebased  cOCT3 a

Covalent organic frameworks are a new class of crystalline organic polymers possessing a high surface area and ordered pores. Judicious selection of building blocks leads to strategic heteroatom inclusion into the COF structure. Owing to their high surface area, exceptional stability and molecular tunability, COFs are adopted for various potential applications. The heteroatoms lining in the pores of COF favor synergistic host-guest interaction to enhance a targeted property. In this report, we have synthesized a resorcinol-phenylenediamine-based COF which selectively adsorbs CO2 into its micropores (12 angstrom). The heat of adsorption value (32 kJ mol(-1)) obtained from the virial model at zero-loading of CO2 indicates its favorable interaction with the framework. Furthermore, we have anchored small-sized Ag nanoparticles (approximate to 4-5 nm) on the COF and used the composite for chemical fixation of CO2 to alkylidene cyclic carbonates by reacting with propargyl alcohols under ambient conditions. Ag@COF catalyzes the reaction selectively with an excellent yield of 90 %. Recyclability of the catalyst has been demonstrated up to five consecutive cycles. The post-catalysis characterizations reveal the integrity of the catalyst even after five reaction cycles. This study emphasizes the ability of COF for simultaneous adsorption and chemical fixation of CO2 into corresponding cyclic carbonates.

10aCO2 capture10acovalent organic frameworks10acyclic carbonates10aPropargyl alcohols10asilver nanoparticles1 aChakraborty, Debanjan1 aShekhar, Pragalbh1 aSingh, Himan, Dev1 aKushwaha, Rinku1 aVinod, C., P.1 aVaidhyanathan, Ramanathan uhttp://library.ncl.res.in/content/ag-nanoparticles-supported-resorcinol-phenylenediamine-based-covalent-organic-framework02284nas a2200313 4500008004100000022001400041245011700055210006900172260000900241300001400250490000600264520120100270653002701471653003101498653002701529653002801556653001901584653001901603100002001622700002901642700002101671700002601692700002101718700001801739700002801757700002501785700003001810856013001840 2020 eng d a2574-097000aNanoporous covalent organic framework embedded with Fe/Fe3O4 nanoparticles as air-stable low-density nanomagnets0 aNanoporous covalent organic framework embedded with FeFe3O4 nano cSEP  a9088-90960 v33 a

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 low-density magnets, which have potential for defense and next-generation aviation applications. Herein, we have grown small Fe/Fe3O4 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 similar to 15,000 mg (300 times heavier). Also, the hydrophobic COF wraps around the Fe/Fe3O4 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.

10aair-stable nanomagnets10aCovalent organic framework10aFe/Fe3O4 nanoparticles10alow-density nanomagnets10amagnetic rayon10ananoporous COF1 aKushwaha, Rinku1 aKaleeswaran, Dhananjayan1 aHaldar, Sattwick1 aChakraborty, Debanjan1 aMullangi, Dinesh1 aBorah, Aditya1 aVinod, Chathakudath, P.1 aMurugavel, Ramaswamy1 aVaidhyanathan, Ramanathan uhttp://library.ncl.res.in/content/nanoporous-covalent-organic-framework-embedded-fefe3o4-nanoparticles-air-stable-low-density02574nas a2200313 4500008004100000022001400041245013000055210006900185260000800254300001200262490000700274520150800281653003201789653001501821653002301836653001701859653002101876653002001897100002001917700002101937700002201958700002201980700001802002700001702020700003602037700003002073700003002103856012702133 2021 eng d a1614-683200aExceptional capacitance enhancement of a non-conducting COF through potential-driven chemical modulation by redox electrolyte0 aExceptional capacitance enhancement of a nonconducting COF throu cAPR a20036260 v113 a

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 I-3(-) 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.

10acovalent organic frameworks10apolyiodide10aredox electrolytes10asolid&\#820810astate capacitors10aSupercapacitors1 aKushwaha, Rinku1 aHaldar, Sattwick1 aShekhar, Pragalbh1 aKrishnan, Akshara1 aSaha, Jayeeta1 aHui, Pramiti1 aVinod, Chathakudath, Prabhakara1 aSubramaniam, Chandramouli1 aVaidhyanathan, Ramanathan uhttp://library.ncl.res.in/content/exceptional-capacitance-enhancement-non-conducting-cof-through-potential-driven-chemical02843nas a2200301 4500008004100000245017400041210006900215260000900284300001400293490000600307520174100313653001202054653001402066653003102080653002802111653001802139653002402157100003702181700002002218700001802238700002202256700002202278700002602300700003602326700003002362700001802392856013102410 2022 eng d00aSynergistic electronic effects in AuCo nanoparticles stabilized in a triazine-based covalent organic framework: a catalyst for methyl orange and methylene blue reduction0 aSynergistic electronic effects in AuCo nanoparticles stabilized  cAPR  a4744-47530 v53 a

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.

10aAuCoCOF10aband gaps10aCovalent organic framework10amethyl orange reduction10aNanoparticles10aUV-vis spectroscopy1 aDevulapalli, Venkata, Swaroopa D1 aKushwaha, Rinku1 aOvalle, Edwin1 aSingh, Himan, Dev1 aShekhar, Pragalbh1 aChakraborty, Debanjan1 aVinod, Chathakudath, Prabhakara1 aVaidhyanathan, Ramanathan1 aBorguet, Eric uhttp://library.ncl.res.in/content/synergistic-electronic-effects-auco-nanoparticles-stabilized-triazine-based-covalent-organic02408nas a2200289 4500008004100000022001400041245011300055210006900168260000800237490000700245520141200252653003201664653002301696653001501719653002301734653002101757100002001778700001801798700002201816700001701838700002701855700001601882700002301898700003601921700003001957856013101987 2023 eng d a1614-683200aMade to measure squaramide COF cathode for zinc dual-ion battery with enriched storage via redox electrolyte0 aMade to measure squaramide COF cathode for zinc dualion battery  cSEP0 v133 a

Aqueous rechargeable batteries are promising grid-scale energy storage devices because of their affordability, operational safety, and environmental benignity. Among these, Zn-ion batteries (ZIBs) have unfolded new horizons. Designing superior cathodes for ZIBs is crucial. Covalent organic frameworks (COFs) can be made redox active with a high storage surface. Here, for the first time, a chelating COF with redox-active ZnI2 in a ZnSO4(aq) electrolyte is combined. Including iodide harvests an approximately threefold enhancement in capacity from 208 to 690 mAh g(-1) at 1.5 A g(-1), the highest among all the COF-derived ZIBs. Remarkably, a charge-discharge curve at 1.3 V exhibits very limited dropout voltage and super-flat platform, with a remarkable capacity of 600 mAh g(-1) at 5 A g(-1) stable up to 6000 cycles, confirming that the polyiodide generation and storage are sustainable. The COF's dual-ion storage (Zn2+ and polyidode) delivers a ZIB with the highest energy density. Spectro-electrochemical measurements coupled with X-ray photoelectron spectroscopy unambiguously unveil the existence of multiple polyiodide species, with I-3(-) and IO3- ions as the prominent species. The latter gets reduced at the COF electrode under an applied potential, leaving I-3(-) as the major species stored on the COF. The prospect of COF-polyiodide((aq)) is a windfall for metal-ion batteries.

10acovalent organic frameworks10aflexible batteries10apolyiodide10aredox electrolytes10aZn ion batteries1 aKushwaha, Rinku1 aJain, Chitvan1 aShekhar, Pragalbh1 aRase, Deepak1 aIllathvalappil, Rajith1 aMekan, Deep1 aCamellus, Augastus1 aVinod, Chathakudath, Prabhakara1 aVaidhyanathan, Ramanathan uhttp://library.ncl.res.in/content/made-measure-squaramide-cof-cathode-zinc-dual-ion-battery-enriched-storage-redox-electrolyte