02343nas a2200217 4500008004100000245013000041210006900171260000800240300002800248490000600276520153100282100002101813700001801834700002201852700002601874700002301900700001801923700002501941700003001966856012901996 2018 eng d00aHigh and reversible lithium ion storage in self-exfoliated triazole-triformyl phloroglucinol-basedcovalent organic nanosheets0 aHigh and reversible lithium ion storage in selfexfoliated triazo cMAR aArticle Number: 17021700 v83 aCovalent organic framework (COF) can grow into self-exfoliated nanosheets. Their graphene/graphite resembling microtexture and nanostructure suits electrochemical applications. Here, covalent organic nanosheets (CON) with nanopores lined with triazole and phloroglucinol units, neither of which binds lithium strongly, and its potential as an anode in Li-ion battery are presented. Their fibrous texture enables facile amalgamation as a coin-cell anode, which exhibits exceptionally high specific capacity of approximate to 720 mA h g(-1) (@100 mA g(-1)). Its capacity is retained even after 1000 cycles. Increasing the current density from 100 mA g(-1) to 1 A g(-1) causes the specific capacity to drop only by 20%, which is the lowest among all high-performing anodic COFs. The majority of the lithium insertion follows an ultrafast diffusion-controlled intercalation (diffusion coefficient, D-Li(+) = 5.48 x 10(-11) cm(2) s(-1)). The absence of strong Li-framework bonds in the density functional theory (DFT) optimized structure supports this reversible intercalation. The discrete monomer of the CON shows a specific capacity of only 140 mA h g(-1) @50 mA g(-1) and no sign of lithium intercalation reveals the crucial role played by the polymeric structure of the CON in this intercalation-assisted conductivity. The potentials mapped using DFT suggest a substantial electronic driving-force for the lithium intercalation. The findings underscore the potential of the designer CON as anode material for Li-ion batteries.1 aHaldar, Sattwick1 aRoy, Kingshuk1 aNandi, Shyamapada1 aChakraborty, Debanjan1 aPuthusseri, Dhanya1 aGawli, Yogesh1 aOgale, Satishchandra1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/high-and-reversible-lithium-ion-storage-self-exfoliated-triazole-triformyl-phloroglucinol02337nas a2200253 4500008004100000022001400041245017500055210006900230260000800299300001600307490000600323520138600329100002601715700002201741700002701763700002101790700001701811700002301828700002101851700002801872700002401900700003001924856012901954 2019 eng d a2470-134300aCarbon derived from soft pyrolysis of a covalent organic framework as a support for small-sized RuO2 showing exceptionally low overpotential for oxygen evolution reaction0 aCarbon derived from soft pyrolysis of a covalent organic framewo cAUG a13465-134730 v43 a

Electrochemical water splitting is the most energy-efficient technique for producing hydrogen and oxygen, the two valuable gases. However, it is limited by the slow kinetics of the anodic oxygen evolution reaction (OER), which can be improved using catalysts. Covalent organic framework (COF)-derived porous carbon can serve as an excellent catalyst support. Here, we report high electrocatalytic activity of two composites, formed by supporting RuO2 on carbon derived from two COFs with closely related structures. These composites catalyze oxygen evolution from alkaline media with overpotentials as low as 210 and 217 mV at 10 mA/cm(2), respectively. The Tafel slopes of these catalysts (65 and 67 mV/dec) indicate fast kinetics compared to commercial RuO2. The observed activity is the highest among all RuO2-based heterogeneous OER catalysts-a touted benchmark OER catalyst. The high catalytic activity arises from the extremely small-sized (similar to 3-4 nm) RuO2 nanoparticles homogeneously dispersed in a micro-mesoporous (BET = 517 m(2)/g) COF-derived carbon. The porous graphenic carbon favors mass transfer, while its N-rich framework anchors the catalytic nanoparticles, making it highly stable and recyclable. Crucially, the soft pyrolysis of the COF enables the formation of porous carbon and simultaneous growth of small RuO2 particles without aggregation.

1 aChakraborty, Debanjan1 aNandi, Shyamapada1 aIllathvalappil, Rajith1 aMullangi, Dinesh1 aMaity, Rahul1 aSingh, Santosh, K.1 aHaldar, Sattwick1 aVinod, Chathakudath, P.1 aKurungot, Sreekumar1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/carbon-derived-soft-pyrolysis-covalent-organic-framework-support-small-sized-ruo2-showing02868nas a2200265 4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520188300310653002502193653003102218653003002249653002802279653002502307100002602332700002202358700002102380700002102401700002802422700003002450856012202480 2019 eng d a1944-824400aCu/Cu2O nanoparticles supported on a phenol-pyridyl COF as a heterogeneous catalyst for the synthesis of unsymmetrical diynes via glaser-hay coupling0 aCuCu2O nanoparticles supported on a phenolpyridyl COF as a heter cMAY  a15670-156790 v113 a

Covalent organic frameworks (COFs) are a new class of porous crystalline polymers with a modular construct that favors fiinctionalization. COF pores can be used to grow nanoparticles (nPs) with dramatic size reduction, stabilize them as dispersions, and provide excellent nP access. Embedding substrate binding sites in COFs can generate host-guest synergy, leading to enhanced catalytic activity. In this report, Cu/Cu2O nPs (2-3 nm) are grown on a COF, which is built by linking a phenolic trialdehyde and a triamine through Schiff bonds. Their micropores restrict the nP to exceptionally small sizes (similar to 2-3 nm), and the pore walls decorated with strategically positioned hydrogen-bonding phenolic groups anchor the substrates via hydrogen-bonding, whereas the basic pyridyl sites serve as cationic species to stabilize the [CuclusterCl2](2-) type reactive intermediates. This composite catalyst shows high activity for Glaser-Hay heterocoupling reactions, an essential 1,3-diyne yielding reaction with widespread applicability in organic synthesis and material science. Despite their broad successes in homocoupled products, preparation of unsymmetrical 1,3-diynes is challenging due to poor selectivity. Here, our COF-based Cu catalyst shows elevated selectivity toward heterocoupling product(s) (Cu nP loading 0.0992 mol %; turn over frequency: similar to 4S-50; turn over number: similar to 17S-190). The reversible redox activity at the Cu centers has been demonstrated by carrying out X-ray photoelectron spectroscopy on the frozen reactions, whereas the crucial interactions between the substrates and the binding sites in their optimized configurations have been modeled using density functional theory methods. This report emphasizes the utility of COFs in developing a heterogeneous catalyst for a truly challenging organic heterocoupling reaction.

10aCopper nanoparticles10aCovalent organic framework10aGlaser-Hay heterocoupling10aheterogeneous catalysis10aunsymmetrical diynes1 aChakraborty, Debanjan1 aNandi, Shyamapada1 aMullangi, Dinesh1 aHaldar, Sattwick1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/cucu2o-nanoparticles-supported-phenol-pyridyl-cof-heterogeneous-catalyst-synthesis02285nas a2200313 4500008004100000022001400041245011700055210006900172260000900241300001400250490000600264520120100270653002701471653003101498653002701529653002801556653001901584653001901603100002001622700002901642700002101671700002601692700002101718700001801739700002801757700002501785700003001810856013101840 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 uhttps://library.ncl.res.in/content/nanoporous-covalent-organic-framework-embedded-fefe3o4-nanoparticles-air-stable-low-density02575nas a2200313 4500008004100000022001400041245013000055210006900185260000800254300001200262490000700274520150800281653003201789653001501821653002301836653001701859653002101876653002001897100002001917700002101937700002201958700002201980700001802002700001702020700003602037700003002073700003002103856012802133 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 uhttps://library.ncl.res.in/content/exceptional-capacitance-enhancement-non-conducting-cof-through-potential-driven-chemical02525nas a2200301 4500008004100000022001400041245011100055210006900166260000800235300001200243490000700255520151500262653002701777653002801804653001701832653002701849653002701876100002101903700001701924700002201941700001801963700003601981700001402017700002302031700001902054700003002073856012002103 2022 eng d a1614-683200aIncorporating conducting polypyrrole into a polyimide COF for carbon-free ultra-high energy supercapacitor0 aIncorporating conducting polypyrrole into a polyimide COF for ca cSEP a22007540 v123 a

Redox-active covalent organic frameworks (COFs) store charges but possess inadequate electronic conductivity. Their capacitive action works by storing H+ ions in an acidic electrolyte and is typically confined to a small voltage window (0-1 V). Increasing this window means higher energy and power density, but this risks COF stability. Advantageously, COF's large pores allow the storage of polarizable bulky ions under a wider voltage thus reaching higher energy density. Here, a COF-electrode-electrolyte system operating at a high voltage regime without any conducting carbon or redox active oxides is presented. Conducting polypyrrole (Ppy) chains are synthesized within a polyimide COF to gain electronic conductivity (approximate to 10 000-fold). A carbon-free quasi-solid-state capacitor assembled using this composite showcases high pseudo-capacitance (358 mF cm(-2)@1 mA cm(-2)) in an aqueous gel electrolyte. The synergy among the redox-active polyimide COF, polypyrrole and organic electrolytes allows a wide-voltage window (0-2.5 V) leading to high energy (145 mu Wh cm(-2)) and power densities (4509 mu W cm(-2)). Amalgamating the polyimide-COF and the polypyrrole as one material minimizes the charge and mass transport resistances. Computation and experiments reveal that even a partial translation of the modules/monomers intrinsic electronics to the COF imparts excellent electrochemical activity. The findings unveil COF-confined polymers as carbon-free energy storage materials.

10acarbon free capacitors10acation-anion co-storage10aconductivity10ahigh energy capacitors10apolypyrrole doped COFs1 aHaldar, Sattwick1 aRase, Deepak1 aShekhar, Pragalbh1 aJain, Chitvan1 aVinod, Chathakudath, Prabhakara1 aZhang, En1 aShupletsov, Leonid1 aKaskel, Stefan1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/incorporating-conducting-polypyrrole-polyimide-cof-carbon-free-ultra-high-energy03138nas a2200253 4500008004100000022001400041245012100055210006900176260000900245300001200254490000600266520224700272100001702519700002702536700002202563700002202585700001802607700002602625700002102651700001902672700003202691700003002723856013102753 2023 eng d a2055-675600aHydroxide ion-conducting viologen-bakelite organic frameworks for flexible solid-state zinc-air battery applications0 aHydroxide ionconducting viologenbakelite organic frameworks for  cJAN  a224-2340 v83 a

Adaptable polymer-based solid-state electrolytes can be a game-changer toward safe, lightweight flexible batteries. We present a robust Bakelite-type organic polymer covalently decked with viologen, triazine, and phenolic moieties. Its flexible structure with cationic viologen centers incorporates counter-balancing free hydroxide ions into the polymeric framework. By design, the aromatic groups and heteroatoms in the framework can be activated under an applied potential to prompt a push-pull drive, setting off the towing of hydroxide ions via weak electrostatic, van der Waals, and hydrogen-bond interactions. The frontier orbitals from a DFT-modeled structure certify this. The hydroxyl-polymer requires minimal KOH wetting to maintain a humid environment for Grotthuss-type transport. The hydroxide ion conductivity reaches a value of 1.4 x 10(-2) S cm(-1) at 80 degrees C and 95% RH, which is retained for over 15 h. We enhanced its practical utility by coating it as a thin solid-state separator-cum-electrolyte on readily available filter paper. The composite exhibits a conductivity of 4.5 x 10(-3) S cm(-1) at 80 degrees C and 95% RH. A zinc-air battery (ZAB) constructed using this polymer-coated paper as electrolyte yields a maximum power density of 115 mW cm(-2) and high specific capacitance of 435 mA h g(-1). The power density recorded for our ZAB is among the best reported for polymer electrolyte-based batteries. Subsequently, the flexible battery fabricated with IISERP-POF11_OH@FilterPaper exhibits an OCV of 1.44 V, and three batteries in series power a demo traffic signal. To underscore the efficiency of hydroxide ion transport through the complex multifunctional backbone of the polymer, we calculated the diffusion coefficient for OH- (Exp: 2.9 x 10(-5) cm(2) s(-1); Comp. 5.2 x 10(-6) cm(2) s(-1)) using electrochemical methods and MD simulations. Climbing-edge NEB calculations reveal a large energy barrier of 2.11 eV for Zn2+ to penetrate the polymer and identify hydroxide ions within the polymer, suggesting no undesirable Zn2+ crossover. Our findings assert the readily accessible C-C-linked cationic polymer's capacity as a solid-state electrolyte for ZABs and any anion-conducting membrane.

1 aRase, Deepak1 aIllathvalappil, Rajith1 aSingh, Himan, Dev1 aShekhar, Pragalbh1 aLeo, Liya, S.1 aChakraborty, Debanjan1 aHaldar, Sattwick1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/hydroxide-ion-conducting-viologen-bakelite-organic-frameworks-flexible-solid-state-zinc-air