02103nas a2200229 4500008004100000022001400041245004000055210004000095260000900135300001600144490000800160520139800168100002501566700002301591700002001614700004901634700003201683700002701715700002501742700003101767856007501798 2015 eng d a1932-744700aChemically chargeable photo battery0 aChemically chargeable photo battery cJUN  a14010-140160 v1193 a

Here we show a surrogate strategy for power production, wherein light is used to actuate a discharge Chemistry in the cathode of an aqueous rechargeable battery (ARB). The proposed photo battery consists of a titaninm nitride photoanode, promising. cathode:material iron(III) hexacyanoferrate(II) as the battery active species, and Na2S2O8 as the chemical charging agent The photo battery delivered negligible capacity in the dark and the capacity shot up to 77.8 mAh/g when artificially shined light, confirming that the battery chemistry is light driven. In the ambient light, the device retained 72% of its artificial light discharge capacity with a stable cycling for more than 100 cycles. Further, an unprecedented means for charging the battery rapidly is presented using Na2S2O8 and it revitalized the battery in 30 s without any external bias. This methodology of expending a photoanode extends to a battery that is free from dissolution of active materials, irreversible structural changes, spontaneous deinsertion reactions, and safety concerns commonly encountered in the state of the art anode materials in ARBs. Apart from bringing out a sustainable way for power production, this device opens up avenues for charging the battery in the likely events of electrical input unavailability, while solving the critcial issues of longer charging time and higher charging voltage.

1 aThimmappa, Ravikumar1 aPaswan, Bhuneshwar1 aGaikwad, Pramod1 aDevendrachari, Mruthyunjayachari, Chattanaha1 aKotresh, Harish, Makri Nimb1 aMohan, Ramsundar, Rani1 aAlias, Joy, Pattayil1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/chemically-chargeable-photo-battery02993nas a2200241 4500008004100000022001400041245012700055210006900182260011000251300001400361490000600375520203600381100003102417700001902448700002502467700002002492700001702512700003102529700001902560700002402579700002002603856012802623 2016 eng d a2046-206900aSolution chemistry-based nano-structuring of copper dendrites for efficient use in catalysis and superhydrophobic surfaces0 aSolution chemistrybased nanostructuring of copper dendrites for  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN a8416-84300 v63 a

Despite their performance and economic advantages over Ag and Au, there have been no focused research efforts on the nano-structuring of Cu dendrites with respect to fine-tuning their structure/morphology towards the efficiency enhancement of suitable applications. Reported here is a simple, versatile, environmentally-friendly and galvanic replacement reaction-based solution chemistry methodology to synthesize highly nano-structured copper dendrites targeted towards the efficiency enhancement of desired applications. Herein, copper is deposited galvanically on an Al foil in the presence of NaCl/HCl, wherein the chloride anions augment an uninterrupted replacement reaction. The growth process of Cu dendrites has been probed in detail. The presence of acid, the type of Cu2+ precursor salt, the Cu2+ ion concentration, the surfactant concentration and the reaction temperature are all demonstrated to provide useful means of modulating the surface structure/morphology of the dendrites. Notably, dendrites formed in the presence of acid are found to be highly nano-structured. Moreover, it is also found that the morphology/structure of the obtained Cu deposit depends considerably upon the choice of the Cu2+ precursor salt, a parameter that has been completely overlooked in the past. The acid-induced nano-structuring of the dendrites is exploited for enhancing their efficiency in the catalytic reduction of para-nitrophenol and for fabricating self-cleaning superhydrophobic surfaces. These nano-structured dendrites are demonstrated to have the highest ever normalized rate constant for the catalytic reduction reaction. Superhydrophobic surfaces fabricated using these dendrites demonstrate excellent self-cleaning abilities, showing a high contact angle (159 degrees) with low contact angle hysteresis (2 degrees). This facile synthetic strategy for the fabrication of highly nano-structured Cu dendrites is expected to open up avenues for the production of Cu-based low-cost functional nano/micro-materials.

1 aBakthavatsalam, Rangarajan1 aGhosh, Subrata1 aBiswas, Ratul, Kumar1 aSaxena, Aayushi1 aRaja, Alagar1 aThotiyl, Musthafa, Ottakam1 aWadhai, Sandip1 aBanpurkar, Arun, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/solution-chemistry-based-nano-structuring-copper-dendrites-efficient-use-catalysis-and-001940nas 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-sensing02183nas 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-electrocatalysis01844nas 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-battery02036nas 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-assembly01780nas 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-ligand00925nas 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-switching00889nas a2200277 4500008004100000022001400041245004200055210004200097260000900139300001600148490000700164653001800171653002600189653002000215653002100235100001800256700003000274700003200304700002900336700002100365700004900386700003600435700003200471700003100503856007700534 2024 eng d a2041-652000aSwitchable molecular electrocatalysis0 aSwitchable molecular electrocatalysis cAUG  a13262-132700 v1510aCO2 reduction10aCOBALT PHTHALOCYANINE10aNANOPOROUS GOLD10aoxygen reduction1 aDutt, Shifali1 aKottaichamy, Alagar, Raja1 aDargily, Neethu, Christudas1 aMukhopadhyay, Sanchayita1 aNayak, Bhojkumar1 aDevendrachari, Mruthyunjayachari, Chattanhal1 aVinod, Chatakudhath, Prabakaran1 aKotresh, Harish, Makri Nimb1 aThotiyl, Musthafa, Ottakam uhttps://library.ncl.res.in/content/switchable-molecular-electrocatalysis