02102nas a2200229 4500008004100000022001400041245004000055210004000095260000900135300001600144490000800160520139800168100002501566700002301591700002001614700004901634700003201683700002701715700002501742700003101767856007401798 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 uhttp://library.ncl.res.in/content/chemically-chargeable-photo-battery02182nas a2200253 4500008004100000022001400041245007600055210006900131260000900200300001200209490000700221520128000228100003001508700001901538700003401557700003201591700004901623700002501672700002501697700003201722700003601754700003101790856010701821 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 uhttp://library.ncl.res.in/content/unprecedented-isomerism-activity-relation-molecular-electrocatalysis01843nas a2200193 4500008004100000245008400041210006900125260000900194300001100203490000700214520111300221100002901334700004901363700002401412700003601436700003201472700003101504856011401535 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 uhttp://library.ncl.res.in/content/regio-isomerism-directed-electrocatalysis-energy-efficient-zinc-air-battery02035nas a2200265 4500008004100000022001400041245008900055210006900144260000800213300001400221490000700235520109600242100003001338700002601368700001401394700003401408700001601442700002501458700004901483700003601532700003201568700002201600700003101622856011601653 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 uhttp://library.ncl.res.in/content/unprecedented-energy-storage-metal-organic-complexes-constitutional-isomerism