01770nas a2200205 4500008004100000022001400041245011600055210006900171260006500240300000800305490000700313520097500320653002301295653002001318653000901338653001501347100003701362700003601399856012901435 2016 eng d a1420-304900aGold incorporated mesoporous silica thin film model surface as a robust SERS and catalytically active substrate0 aGold incorporated mesoporous silica thin film model surface as a aST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLANDbMDPI AGcMAY a6670 v213 a

Ultra-small gold nanoparticles incorporated in mesoporous silica thin films with accessible pore channels perpendicular to the substrate are prepared by a modified sol-gel method. The simple and easy spin coating technique is applied here to make homogeneous thin films. The surface characterization using FESEM shows crack-free films with a perpendicular pore arrangement. The applicability of these thin films as catalysts as well as a robust SERS active substrate for model catalysis study is tested. Compared to bare silica film our gold incorporated silica, GSM-23F gave an enhancement factor of 10(3) for RhB with a laser source 633 nm. The reduction reaction of p-nitrophenol with sodium borohydride from our thin films shows a decrease in peak intensity corresponding to -NO2 group as time proceeds, confirming the catalytic activity. Such model surfaces can potentially bridge the material gap between a real catalytic system and surface science studies.

10agold nanoparticles10amodel catalysis10aSERS10aThin films1 aSekhar, Anandakumari, Chandrasek1 aVinod, Chathakudath, Prabhakara uhttps://library.ncl.res.in/content/gold-incorporated-mesoporous-silica-thin-film-model-surface-robust-sers-and-catalytically02284nas a2200265 4500008004100000022001400041245012300055210006900178260000900247300001400256490000700270520141500277653000901692653001801701653001001719653001901729653001601748653001301764100002001777700001801797700003601815700001901851700002501870856012301895 2019 eng d a1944-824400aDirect Z-scheme g-C3N4/FeWO4 nanocomposite for enhanced and selective photocatalytic CO2 reduction under visible light0 aDirect Zscheme gC3N4FeWO4 nanocomposite for enhanced and selecti cFEB  a6174-61830 v113 a

Photocatalytic reduction of CO2 to renewable solar fuels is considered to be a promising strategy to simultaneously solve both global warming and energy crises. However, development of a superior photocatalytic system with high product selectivity for CO2 reduction under solar light is the prime requisite. Herein, a series of nature-inspired Z-scheme g C3N4/FeWO4 composites are prepared for higher performance and selective CO2 reduction to CO as solar fuel under solar light. The novel direct Z-scheme coupling of the visible light-active FeWO4 nanoparticles with C3N4 nanosheets is seen to exhibit excellent performance for CO production with a rate of 6 mu mol/g/h at an ambient temperature, almost 6 times higher compared to pristine C3N4 and 15 times higher than pristine FeWO4. More importantly, selectivity for CO is 100% over other carbon products from CO, reduction and more than 90% over. H-2 products from water splitting. Our results clearly demonstrate that the staggered band structure between FeWO4 and C3N4 reflecting the nature-inspired Z-scheme system not only favors superior spatial separation of the electron hole pair in g-C3N4/FeWO4 but also shows good reusability. The present work provides unprecedented insights for constructing the direct Z-scheme by mimicking the nature for high performance and selective photocatalytic CO2 reduction into solar fuels under solar light.

10aC3N410aCO2 reduction10aFeWO410aPhotocatalysis10asolar fuels10aZ-scheme1 aBhosale, Reshma1 aJain, Srashti1 aVinod, Chathakudath, Prabhakara1 aKumar, Santosh1 aOgale, Satishchandra uhttps://library.ncl.res.in/content/direct-z-scheme-g-c3n4fewo4-nanocomposite-enhanced-and-selective-photocatalytic-co201940nas a2200229 4500008004100000022001400041245005900055210005900114260000800173300001400181490000700195520116800202100003001370700001901400700004801419700002501467700002501492700003201517700003601549700003101585856009401616 2020 eng d a0003-270000aGeometrical isomerism directed electrochemical sensing0 aGeometrical isomerism directed electrochemical sensing cMAR a4541-45470 v923 a

We report the independent role of isomerism of secondary sphere substituents over their nature, a factor often overlooked in molecular electrocatalysis pertaining to electrochemical sensing, by establishing that isomerism redefines the electronic structure at the catalytic reaction center via geometrical factors. UV-vis spectroscopy and X-ray photoelectron spectroscopy suggest that a substituent's isomerism in molecular catalysts conjoins molecular planarity and catalytic activation through competing field effects and resonance effects. As a classical example, we demonstrate the influence of isomerism of the -NO2 substituents for the electrocatalytic multi electron oxidation of As(III), a potentially important electrochemical pathway for water remediation and arsenic detection. The isomerism dependent oxidative activation of catalytic center leads to a nonprecious molecular catalyst capable for direct As(III) oxidation with an experimental detection limit close to WHO guidelines. This work opens up an unusual approach in analytical chemistry for developing various sensing platforms for challenging chemical and electrochemical reactions.

1 aKottaichamy, Alagar, Raja1 aBegum, Shabbah1 aDevendrachari, Mruthyunjayachar, Chattanaha1 aBhat, Zahid, Manzoor1 aThimmappa, Ravikumar1 aKotresh, Harish, Makri Nimb1 aVinod, Chathakudath, Prabhakara1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/geometrical-isomerism-directed-electrochemical-sensing01617nas a2200265 4500008004100000022001400041245010300055210006900158260000800227300001400235490000600249520073700255653001800992653002001010653001501030653000901045653003001054653000901084100002301093700002101116700002201137700003601159700002501195856013101220 2020 eng d a2574-096200aTweaking palladium electronic structure to attain oxygen reduction activity superior to platinum/C0 aTweaking palladium electronic structure to attain oxygen reducti cJUL a6127-61320 v33 a

Enhancing oxygen reduction (ORR) activity through alloying is crucial to improve the performance of a fuel-cell catalysts. In this work, we have studied the alloying effects of 4f rare-earth (RE) metals with palladium. The modified catalyst exhibits better activity (E-onset = 1 V and E-1/2 = 0.88 V) and higher selectivity toward H2O (similar to 97%) compared to the state-of-the-art catalysts due to complete dissociation of O-2. Hirshfeld charge analysis and 2D-electron localization function reveal improved adsorbate-adsorbent interaction on the catalyst surface. This work paves a strategy to design highly selective non-Pt-based catalysts for the ORR by controlling electronic structures and surface oxide formation.

10ad-band center10aDFT calculation10adurability10aEuPd10aoxygen reduction reaction10aYbPd1 aSarma, Saurav, Ch.1 aKaja, Sai, Manoj1 aMishra, Vidyanshu1 aVinod, Chathakudath, Prabhakara1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/tweaking-palladium-electronic-structure-attain-oxygen-reduction-activity-superior-platinumc02183nas a2200253 4500008004100000022001400041245007600055210006900131260000900200300001200209490000700221520128000228100003001508700001901538700003401557700003201591700004901623700002501672700002501697700003201722700003601754700003101790856010801821 2020 eng d a1948-718500aUnprecedented isomerism-activity relation in molecular electrocatalysis0 aUnprecedented isomerismactivity relation in molecular electrocat cJAN  a263-2710 v113 a

The role of electrocatalysts in energy storage/conversion, biomedical and environmental sectors, green chemistry, and much more has generated enormous interest in comprehending their structure-activity relations. While targeting the surface-to-volume ratio, exposing reactive crystal planes and interfacial modifications are time-tested considerations for activating metallic catalysts; it is primarily by substitution in molecular electrocatalysts. This account draws the distinction between a substituent's chemical identity and isomerism, when regioisomerism of the -NO2 substituent is conferred at the ``alpha'' and ``beta'' positions on the macrocycle of cobalt phthalocyanines. Spectroscopic analysis and theoretical calculations establish that the beta isomer accumulates catalytically active intermediates via a cumulative influence of inductive and resonance effects. However, the field effect in the alpha isomer restricts this activation due to a vanishing resonance effect. The demonstration of the distinct role of isomerism in substituted molecular electrocatalysts for reactions ranging from energy conversion to biosensing highlights that isomerism of the substituents makes an independent contribution to electrocatalysis over its chemical identity.

1 aKottaichamy, Alagar, Raja1 aBegum, Shabbah1 aNazrulla, Mohammed, Azeezulla1 aDargily, Neethu, Christudas1 aDevendrachari, Mruthyunjayachari, Chattanaha1 aBhat, Zahid, Manzoor1 aThimmappa, Ravikumar1 aKotresh, Harish, Makri Nimb1 aVinod, Chathakudath, Prabhakara1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/unprecedented-isomerism-activity-relation-molecular-electrocatalysis02575nas 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-energy01844nas a2200193 4500008004100000245008400041210006900125260000900194300001100203490000700214520111300221100002901334700004901363700002401412700003601436700003201472700003101504856011501535 2022 eng d00aRegio-isomerism directed electrocatalysis for energy efficient zinc-air battery0 aRegioisomerism directed electrocatalysis for energy efficient zi cOCT  a1051790 v253 a

We have investigated the role of ligand isomerism in modulating the mechanisms and kinetics associated with charge/ discharge chemistry of an aqueous metal-air battery. The dominant electron-withdrawing inductive effect (-I effect) and the diminished electron-withdrawing resonance effect (-R effect) in the alpha-NO2 isomer noticeably diminishes the rate of oxygen reduction (ORR) and oxygen evolution reactions (OER) on the catalytic Co-center. In their beta-counterpart, the cumulative -I and -R effects noticeably enhance the OER and ORR kinetics on the same catalytic Co-center. Therefore, the regioisomerism of the -NO2 functionality amplifies the kinetics of ORR/OER without influencing their mechanistic pathways. When isomeric electrocatalysts are integrated to aid the charge chemistry of a Zn-air battery, the overpotential could be decreased by similar to 250mV with beta-NO2 isomer leading to a round-trip efficiency as high as 60%. This work contributes to the design of novel molecular platforms to target the overall round-trip efficiency of energy storage and conversion devices.

1 aMukhopadhyay, Sanchayita1 aDevendrachari, Mruthyunjayachari, Chattanaha1 aKanade, Sandeep, C.1 aVinod, Chathakudath, Prabhakara1 aKotresh, Harish, Makri Nimb1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/regio-isomerism-directed-electrocatalysis-energy-efficient-zinc-air-battery02844nas a2200301 4500008004100000245017400041210006900215260000900284300001400293490000600307520174100313653001202054653001402066653003102080653002802111653001802139653002402157100003702181700002002218700001802238700002202256700002202278700002602300700003602326700003002362700001802392856013202410 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 uhttps://library.ncl.res.in/content/synergistic-electronic-effects-auco-nanoparticles-stabilized-triazine-based-covalent-organic02409nas a2200289 4500008004100000022001400041245011300055210006900168260000800237490000700245520141200252653003201664653002301696653001501719653002301734653002101757100002001778700001801798700002201816700001701838700002701855700001601882700002301898700003601921700003001957856013201987 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 uhttps://library.ncl.res.in/content/made-measure-squaramide-cof-cathode-zinc-dual-ion-battery-enriched-storage-redox-electrolyte02348nas a2200265 4500008004100000022001400041245014300055210006900198260000800267300001200275490000800287520138500295653003201680653002801712100001801740700002001758700001701778700002201795700001901817700001901836700003201855700003601887700003001923856012901953 2023 eng d a0002-786300aTailoring COFs: transforming nonconducting 2D layered COF into a conducting quasi-3D architecture via interlayer knitting with polypyrrole0 aTailoring COFs transforming nonconducting 2D layered COF into a  cDEC a487-4990 v1463 a

Improving the electronic conductivity and the structural robustness of covalent organic frameworks (COFs) is paramount. Here, we covalently cross-link a 2D COF with polypyrrole (Ppy) chains to form a quasi-3D COF. The 3D COF shows well-defined reflections in the SAED patterns distinctly indexed to its modeled crystal structure. This knitting of 2D COF layers with conjugated polypyrrole units improves electronic conductivity from 10(-9) to 10(-2 )S m(-1). This conductivity boost is affirmed by the presence of density of states near the Fermi level in the 3D COF, and this elevates the COF's valence band maximum by 0.52 eV with respect to the parent 2D pyrrole-functionalized COF, which agrees well with the opto-electro band gaps. The extent of HOMO elevation suggests the predominant existence of a polaron state (radical cation), giving rise to a strong EPR signal, most likely sourced from the cross-linking polypyrrole chains. A supercapacitor devised with COF20-Ppy records a high areal capacitance of 377.6 mF cm(-2), higher than that of the COF loaded with noncovalently linked polypyrrole chains. Thus, the polypyrrole acts as a ``conjugation bridge'' across the layers, lowering the band gap and providing polarons and additional conduction pathways. This marks a far-reaching approach to converting many 2D COFs into highly ordered and conducting 3D ones.

10acovalent organic frameworks10aElectrical conductivity1 aJain, Chitvan1 aKushwaha, Rinku1 aRase, Deepak1 aShekhar, Pragalbh1 aShelke, Ankita1 aSonwani, Disha1 aAjithkumar, Thalasseril, G.1 aVinod, Chathakudath, Prabhakara1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/tailoring-cofs-transforming-nonconducting-2d-layered-cof-conducting-quasi-3d-architecture02036nas a2200265 4500008004100000022001400041245008900055210006900144260000800213300001400221490000700235520109600242100003001338700002601368700001401394700003401408700001601442700002501458700004901483700003601532700003201568700002201600700003101622856011701653 2023 eng d a2041-652000aUnprecedented energy storage in metal-organic complexes via constitutional isomerism0 aUnprecedented energy storage in metalorganic complexes via const cJUN a6383-63920 v143 a

The essence of any electrochemical system is engraved in its electrical double layer (EDL), and we report its unprecedented reorganization by the structural isomerism of molecules, with a direct consequence on their energy storage capability. Electrochemical and spectroscopic analyses in combination with computational and modelling studies demonstrate that an attractive field-effect due to the molecule's structural-isomerism, in contrast to a repulsive field-effect, spatially screens the ion-ion coulombic repulsions in the EDL and reconfigures the local density of anions. In a laboratory-level prototype supercapacitor, those with beta-structural isomerism exhibit nearly 6-times elevated energy storage compared to the state-of-the-art electrodes, by delivering similar to 535 F g(-1) at 1 A g(-1) while maintaining high performance metrics even at a rate as high as 50 A g(-1). The elucidation of the decisive role of structural isomerism in reconfiguring the electrified interface represents a major step forward in understanding the electrodics of molecular platforms.

1 aKottaichamy, Alagar, Raja1 aDeebansok, Siraprapha1 aDeng, Jie1 aNazrulla, Mohammed, Azeezulla1 aZhu, Yachao1 aBhat, Zahid, Manzoor1 aDevendrachari, Mruthyunjayachari, Chattanaha1 aVinod, Chathakudath, Prabhakara1 aKotresh, Harish, Makri Nimb1 aFontaine, Olivier1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/unprecedented-energy-storage-metal-organic-complexes-constitutional-isomerism01948nas a2200229 4500008004100000022001400041245009900055210006900154260000900223300001400232490000700246520110500253100002901358700003001387700003001417700002101447700003601468700003201504700002401536700003101560856012701591 2023 eng d a1948-718500aUnusual ligand assistance in molecular electrocatalysis via interfacial proton charge assembly0 aUnusual ligand assistance in molecular electrocatalysis via inte cJUN  a5377-53850 v143 a

We show that the ability of the ligand to reorganizethe electricdouble layer (EDL) often dominates the electrocatalysis contrary totheir inductive effect in the spectrochemical series, leading to counterintuitiveelectrocatalysis. With water oxidation and chlorine evolution as theprobe reactions, the same catalytic entity with carboxy functionalizedligand exhibited surprisingly higher electrochemical activity in comparisonto the aggressively electron-withdrawing nitro functionalized ligands,which is contrary to their actual location in the spectrochemicalseries. Spectroscopic and electrochemical analyses suggest the enrichmentof catalytically active species in the carboxy substituted ligandvia proton charge assembly in the EDL that in turn enhances the kineticsof the overall electrochemical process. This demonstration of lessobvious ligands becoming indispensable in electrocatalysis suggestsa blind designing of ligands solely based on their inductive effectshould be reconsidered as it will prevent the utilization of the maximumpotential of the molecule in electrocatalysis.

1 aMukhopadhyay, Sanchayita1 aKottaichamy, Alagar, Raja1 aChame, Pallavi, Vyankuram1 aGhosh, Prasenjit1 aVinod, Chathakudath, Prabhakara1 aKotresh, Harish, Makri Nimb1 aKanade, Sandeep, C.1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/unusual-ligand-assistance-molecular-electrocatalysis-interfacial-proton-charge-assembly03376nas a2200337 4500008004100000022001400041245023000055210006900285260000800354490000700362520209900369653000702468653002602475653001402501653002702515653001802542653003002560653003002590653003402620653003402654100003002688700002002718700003302738700001802771700002702789700002002816700001802836700003602854700002402890856012402914 2024 eng d a1613-681000aAluminium, nitrogen-dual-doped reduced graphene oxide Co-existing with cobalt-encapsulated graphitic carbon nanotube as an activity modulated electrocatalyst for oxygen electrocatalyst for oxygen electrochemistry applications0 aAluminium nitrogendualdoped reduced graphene oxide Coexisting wi cAUG0 v203 a

There is a rising need to create high-performing, affordable electrocatalysts in the new field of oxygen electrochemistry. Here, a cost-effective, activity-modulated electrocatalyst with the capacity to trigger both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in an alkaline environment is presented. The catalyst (Al, Co/N-rGCNT) is made up of aluminium, nitrogen-dual-doped reduced graphene oxide sheets co-existing with cobalt-encapsulated carbon nanotube units. Based on X-ray Absorption Spectroscopy (XAS) studies, it is established that the superior reaction kinetics in Al, Co/N-rGCNT over their bulk counterparts can be attributed to their electronic regulation. The Al, Co/N-rGCNT performs as a versatile bifunctional electrocatalyst for zinc-air battery (ZAB), delivering an open circuit potential approximate to 1.35 V and peak power density of 106.3 mW cm-2, which are comparable to the system based on Pt/C. The Al, Co/N-rGCNT-based system showed a specific capacity of 737 mAh gZn-1 compared to 696 mAh gZn-1 delivered by the system based on Pt/C. The DFT calculations indicate that the adsorption of Co in the presence of Al doping in NGr improves the electronic properties favoring ORR. Thus, the Al, Co/N-rGCNT-based rechargeable ZAB (RZAB) emerges as a highly viable and affordable option for the development of RZAB for practical applications. This manuscript reports the development of a new bifunctional catalyst that exhibits high activity and stability under practical operating conditions. The catalyst (Al, Co/N-rGCNT) is made up of aluminium, nitrogen-dual-doped reduced graphene oxide sheets co-existing with the in situ formed cobalt-encapsulated CNT units is synthesized by a scalable pyrolysis method in an inert Ar atmosphere. The developed electrocatalyst achieved enhanced the oxygen reduction reaction (ORR) and the oxygen evolution reaction OER activity as a result of the favorable synergistic modulations and the system can serve as a process-friendly air-electrode for rechargeable zinc-air battery (RZAB). image

10aAl10aBifunctional catalyst10aDFT study10aencapsulated structure10aN-dual doping10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable zinc-air battery10aX-ray absorption spectroscopy1 aKharabe, Geeta, Pandurang1 aBarik, Sidharth1 aVeeranmaril, Sudheesh, Kumar1 aNair, Aathira1 aIllathvalappil, Rajith1 aYoyakki, Athira1 aJoshi, Kavita1 aVinod, Chathakudath, Prabhakara1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/aluminium-nitrogen-dual-doped-reduced-graphene-oxide-co-existing-cobalt-encapsulated01780nas a2200217 4500008004100000022001400041245011300055210006900168260000900237300001400246490000700260520093400267100002901201700003001230700004901260700002701309700003201336700003601368700003101404856012701435 2024 eng d a2041-652000aElectrochemical energy storage in an organic supercapacitor via a non-electrochemical proton charge assembly0 aElectrochemical energy storage in an organic supercapacitor via  cJAN  a1726-17350 v153 a

Contrary to conventional beliefs, we show how a functional ligand that does not exhibit any redox activity elevates the charge storage capability of an electric double layer via a proton charge assembly. Compared to an unsubstituted ligand, a non-redox active carboxy ligand demonstrated nearly a 4-fold increase in charge storage, impressive capacitive retention even at a rate of 900C, and approximately a 2-fold decrease in leakage currents with an enhancement in energy density up to approximately 70% via a non-electrochemical route of proton charge assembly. Generalizability of these findings is presented with various non-redox active functional units that can undergo proton charge assembly in the ligand. This demonstration of non-redox active functional units enriching supercapacitive charge storage via proton charge assembly contributes to the rational design of ligands for energy storage applications.

1 aMukhopadhyay, Sanchayita1 aKottaichamy, Alagar, Raja1 aDevendrachari, Mruthyunjayachari, Chattanaha1 aMendhe, Rahul, Mahadeo1 aKotresh, Harish, Makri Nimb1 aVinod, Chathakudath, Prabhakara1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/electrochemical-energy-storage-organic-supercapacitor-non-electrochemical-proton-charge01731nas a2200229 4500008004100000022001400041245011500055210006900170260000800239300001400247490000700261520088800268100002701156700001901183700003001202700002001232700003201252700003601284700002501320700003101345856012501376 2024 eng d a1463-926200aFuel from waste: electrosynthesizing ammonia directly from agricultural digestate through ligand isomerization0 aFuel from waste electrosynthesizing ammonia directly from agricu cJUN a6490-65000 v263 a

We demonstrate that the catalytic metal centre for ammonia production can be selectively activated with only a slight alteration in ligand isomerization (alpha and beta isomers), making it practical and effective even for agricultural effluents. With almost 90% faradaic efficiency, the beta isomer generates approximately 0.64 mg h-1 cm-2 of ammonia. Energy-efficient ammonia recovery is made possible by the interfacial proton charge assembly that beta-isomerization creates, which attracts the reacting nitrate and repels the competing hydronium ions. With minimal energy consumption, this isomerization approach can interconvert agricultural effluents into ammonia fuel, reaching up to 84% of its theoretical yield and maintaining stability over 100 hours of continuous electrolysis. Ligand isomerization driven ammonia electrosynthesis from agricultural waste water.

1 aMendhe, Rahul, Mahadeo1 aMondal, Ritwik1 aKottaichamy, Alagar, Raja1 aHaridas, Akshay1 aKotresh, Harish, Makri Nimb1 aVinod, Chathakudath, Prabhakara1 aThimmappa, Ravikumar1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/fuel-waste-electrosynthesizing-ammonia-directly-agricultural-digestate-through-ligand01441nas a2200181 4500008004100000022001400041245008500055210006900140260000900209300001400218490000700232520080200239100002401041700003601065700002101101700003201122856010501154 2024 eng d a0888-588500aKinetic model of hydrogenation of glucose to sorbitol on a Ni/Bentonite catalyst0 aKinetic model of hydrogenation of glucose to sorbitol on a NiBen cMAR  a4771-47810 v633 a

In the present work, we studied the hydrogenation of glucose to sorbitol using a nickel/bentonite catalyst. The Ni/bentonite catalyst was prepared by the wet impregnation method and characterized by different methods to understand the catalyst surface morphology, surface area, metal content, pore size, etc. Different reaction parameters such as temperature, hydrogen pressure, metal loading, catalyst loading, and agitation speed were studied to achieve a glucose conversion of 96.8% and a sorbitol selectivity of 95.3%. The reusability test was performed to examine the stability of the catalyst. The kinetic models such as the Eley-Rideal and Langmuir-Hinshelwood-Hougen-Watson models were used to study the hydrogenation of glucose and activation energy required for the reaction.

1 aPandya, Harmitkumar1 aVinod, Chathakudath, Prabhakara1 aRathod, Virendra1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/kinetic-model-hydrogenation-glucose-sorbitol-nibentonite-catalyst00925nas a2200277 4500008004100000022001400041245005900055210005900114260000800173490000700181653001400188653001800202653001800220653002100238100003000259700003400289700001900323700002500342700004900367700003600416700002000452700003200472700001800504700003100522856009400553 2024 eng d a1433-785100aLigand isomerization driven electrocatalytic switching0 aLigand isomerization driven electrocatalytic switching cJUL0 v6310aCatalysts10aCO2 reduction10aO-2 REDUCTION10aoxygen reduction1 aKottaichamy, Alagar, Raja1 aNazrulla, Mohammed, Azeezulla1 aParmar, Muskan1 aThimmappa, Ravikumar1 aDevendrachari, Mruthyunjayachari, Chattanaha1 aVinod, Chathakudath, Prabhakara1 aVolokh, Michael1 aKotresh, Harish, Makri Nimb1 aShalom, Menny1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/ligand-isomerization-driven-electrocatalytic-switching01101nas a2200325 4500008004100000022001400041245015200055210006900207260000800276300001400284490000700298653001500305653001300320653002000333653001400353100002200367700001800389700002200407700002000429700001700449700002200466700001800488700001800506700001900524700003600543700001500579700002300594700003000617856012800647 2024 eng d a0897-475600aResorcinol-Azodianiline Covalent Organic Framework Supported FeOOH Quantum Dot-Catalyzed Electrochemical Ammonia Synthesis under Ambient Conditions0 aResorcinolAzodianiline Covalent Organic Framework Supported FeOO cAUG a8229-82380 v3610aconversion10anitrogen10aRecent Progress10areduction1 aShekhar, Pragalbh1 aKosugi, Kento1 aSingh, Himan, Dev1 aKushwaha, Rinku1 aRase, Deepak1 aMatsuzaki, Takumi1 aJain, Chitvan1 aSingh, Piyush1 aSingh, Yashraj1 aVinod, Chathakudath, Prabhakara1 aKondo, Mio1 aMasaoka, Shigeyuki1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/resorcinol-azodianiline-covalent-organic-framework-supported-feooh-quantum-dot-catalyzed02439nas a2200229 4500008004100000022001400041245014500055210006900200260000900269300001600278490000700294520156000301100001901861700002901880700001901909700002101928700003201949700003201981700003602013700003102049856012902080 2024 eng d a1477-922600aSynergistic effects of the substrate-ligand interaction in metal-organic complexes on the de-electronation kinetics of a vitamin C fuel cell0 aSynergistic effects of the substrateligand interaction in metalo cAUG  a13384-133930 v533 a

The rising demand for portable energy conversion devices has spurred the advancement of direct liquid fuel cells (DLFCs) employing fuels such as alcohol, ammonia, hydrazine, and vitamin C. In these devices, various precious metal platforms have been explored to increase the de-electronation kinetics and reduce catalyst poisoning, but with substantial cost implications. We demonstrate the crucial role of ligands in non-precious organometallic complexes in influencing the de-electronation kinetics of fuel molecules through a unique substrate-ligand synergistic interaction. This unique chemistry imparts electron deficiency at the catalytic metal center while simultaneously populating the ligand with an extensive proton charge assembly. This distinct substrate-ligand interaction enhances the DLFC performance by coulombically dragging the substrate with a distinct amplification in its de-electronation kinetics. By integrating this approach with a ferricyanide/ferrocyanide half-cell reaction, a precious metal-free vitamin C fuel cell is developed, which is capable of generating an open circuit voltage of similar to 950 mV, a peak power density of similar to 97 mW cm-2 at a peak current density of similar to 215 mA cm-2 with the performance metrics nearly 1.7 times higher than a precious metal based DLFC. This highlights the potential of the substrate-ligand synergy in the design of efficient molecular catalysts for energy conversion applications. A precious metal-free biomass fuel cell through substrate-ligand interactions.

1 aParmar, Muskan1 aMukhopadhyay, Sanchayita1 aMondal, Ritwik1 aNayak, Bhojkumar1 aDargily, Neethu, Christudas1 aKotresh, Harish, Makri Nimb1 aVinod, Chathakudath, Prabhakara1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/synergistic-effects-substrate-ligand-interaction-metal-organic-complexes-de-electronation01948nas a2200193 4500008004100000022001400041245010200055210006900157260000800226300001600234490000700250520124600257100001701503700001901520700003601539700002101575700003201596856012601628 2025 eng d a0888-588500aAldol Condensation of Furfural with Acetone by Using Mg-Al-O-t-Bu HT Catalyst and Kinetic Studies0 aAldol Condensation of Furfural with Acetone by Using MgAlOtBu HT cDEC a24938-249480 v643 a

An environment-friendly method for producing jet fuel precursors involves the aldol condensation of biomass-derived chemicals. In this study, the condensation reaction between furfural and acetone was performed using a Mg-Al-O-t-Bu hydrotalcite (HT) catalyst, achieving a furfural conversion of 99% and a selectivity of 82% toward 4-(2-furyl)-3-buten-2-one (FAc). The kinetics of the process were evaluated using a Langmuir-Hinshelwood-Hougen-Watson (LHHW) model across a range of temperatures, and the model showed an excellent fit to the experimental data. The effect of different catalysts, reaction temperatures, catalyst loadings, molar ratios, and reaction times was systematically investigated. The Mg-Al-O-t-Bu HT catalyst was extensively analyzed through techniques such as XRD, XPS, FTIR, nitrogen adsorption-desorption measurements, and CO2-TPD. The catalyst exhibited excellent stability, maintaining its performance consistently across five successive reaction cycles with no notable decline in activity. These findings highlight the industrial relevance of Mg-Al-O-t-Bu HT as a robust and recyclable solid base catalyst for biomass upgrading, with strong potential for process scale-up in renewable fuel production.

1 aPatil, Sneha1 aKamble, Paresh1 aVinod, Chathakudath, Prabhakara1 aRathod, Virendra1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/aldol-condensation-furfural-acetone-using-mg-al-o-t-bu-ht-catalyst-and-kinetic-studies