02644nas a2200265 4500008004100000245012200041210006900163260000900232300001400241490000600255520168400261653002901945653003401974653002102008653003002029653002502059653003002084100001902114700002302133700002802156700002402184700002402208700002102232856012502253 2021 eng d00aSeed-mediated growth of Pt on high-index faceted Au nanocrystals: the ag lining and implications for electrocatalysis0 aSeedmediated growth of Pt on highindex faceted Au nanocrystals t cSEP  a9155-91660 v43 aBimetallic Au@Pt nanocrystals (NCs) offer a unique combination of plasmonic and catalytic properties and are a growing field of research. Herein, we report an unusual observation in the behavior of silver ions (Ag+) which was found to play a dominant role in dictating the Pt deposition in a seed-mediated growth method. `While the literature is replete with various instances of Ag-assisted Pt deposition whereby higher concentration of Ag+ translates into a thicker Pt shell, in the present study, contradictory observations were made. In the presence of lower amounts of Ag+, thick Pt shells were visualized, while at higher concentrations of Ag+, the extent of Pt deposition via the galvanic replacement reaction was reduced. Additionally, the presence of Ag was deemed necessary for the Pt deposition to take place, either in the form of an underpotential deposition layer on the Au NCs or by introducing Ag+ in the growth solution. We have demonstrated our findings on two different Au NCs enclosed with high-index facets, concave cuboid, and elongated tetrahexahedra, which mirror similar observations and provide generality to our claim. To the best of our knowledge, the time required for Pt deposition on the Au core in the present work is the least among the reported seed-mediated routes. Furthermore, this work, besides presenting a facile and general route for the amalgamation of catalytic and plasmonic properties in hybrid Pt-Au NCs, sheds light on the mechanistic aspects of Ag-assisted wet-chemical generation of bimetallic Au@Pt NCs. The overall electrocatalytic performance of our Au@Pt NCs toward the oxygen reduction reaction was realized to be impressive.10abimetallic nanostructure10agalvanic replacement reaction10ahigh-index facet10aoxygen reduction reaction10aseed-mediated growth10aunderpotential deposition1 aRoy, Debashree1 aRajendra, Ranguwar1 aGangadharan, Pranav, K.1 aPandikassala, Ajmal1 aKurungot, Sreekumar1 aBallav, Nirmalya uhttps://library.ncl.res.in/content/seed-mediated-growth-pt-high-index-faceted-au-nanocrystals-ag-lining-and-implications02706nas a2200265 4500008004100000022001400041245013400055210006900189260000900258300001400267490000700281520178300288653001802071653002002089653001402109653002102123653001702144653002002161653002202181653003002203100002802233700002402261700002402285856013102309 2021 eng d a1944-824400aToward pH independent oxygen reduction reaction by polydopamine derived 3D interconnected, iron carbide embedded graphitic carbon0 aToward pH independent oxygen reduction reaction by polydopamine  cFEB  a8147-81580 v133 a

Recent advancements on the development of nonprecious electrocatalysts with iron (Fe) incorporated active centers have generated confidence on realizing cost-effective proton exchange membrane fuel cells (PEMFCs). However, most of these catalysts that emerged as a substitution for the platinum supported on carbon (Pt/C) catalysts in oxygen reduction reaction (ORR) are active under basic conditions, and their feasibility in PEMFCs remains as a challenge. In this scenario, this work reports the synthesis of a Pt-free oxygen reduction electrocatalyst prepared by the annealing of polydopamine grown melamine foam. The prepared catalyst has a three-dimensional (3D) interconnected bilayer network structure possessing the carbon nitride backbone wrapped by graphitic carbon layer bearing iron carbides and nitrides as the active centers (3DFePDC). Interestingly, the 3D-FePDC catalyst displayed an ORR activity both under acidic and basic conditions. Whereas the ORR performance of 3D-FePDC closely matches that of the commercial Pt/C in the basic medium, it displays only a low overpotential value of 60 mV under acidic conditions compared to its Pt counterpart. The kinetics of ORR on 3DFePDC is found to be similar to the four-electron (4e) reduction pathway displayed by Pt/C. Testing of a PEMFC in a single cell mode by using 3D-FePDC as the cathode catalyst and Nafion membrane delivered a maximum power density of 278 mW cm(-2), which is a promising value expected from a system based on the nonprecious metal cathode. Ultimately, as a cost-effective catalyst that can effectively perform irrespective of the pH conditions, 3D-FePDC offers significant prospects in the areas like fuel cells and metal-air batteries which work in acidic and/or basic conditions.

10aacidic medium10aelectrocatalyst10afuel cell10agraphitic carbon10aIron carbide10anitrogen doping10anonprecious metal10aoxygen reduction reaction1 aGangadharan, Pranav, K.1 aPandikassala, Ajmal1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/toward-ph-independent-oxygen-reduction-reaction-polydopamine-derived-3d-interconnected-iron02600nas a2200265 4500008004100000022001400041245017300055210006900228260000800297300001600305490000700321520162900328653003101957653002201988653002302010653002202033653002002055100002102075700002402096700002402120700002402144700001802168700002402186856012402210 2022 eng d a1944-824400aCo-Ni layered double hydroxide for the electrocatalytic oxidation of organic molecules: an approach to lowering the overall cell voltage for the water splitting process0 aCoNi layered double hydroxide for the electrocatalytic oxidation cAPR a16222-162320 v143 a

Electrocatalytic oxidation of simple organic molecules oilers a promising strategy to combat the sluggish kinetics of the water oxidation reaction (WOR). The low potential requirement, inhibition of the crossover of gases, and formation of value-added products at the anode are benefits of the electrocatalytic oxidation of organic molecules. Herein, we developed cobalt-nickel-based layered double hydroxide (LDH) as a robust material for the electrocatalytic oxidation of alcohols and urea at the anode, replacing the WOR. A facile synthesis protocol to form LDHs with different ratios of Co and Ni is adapted. It demonstrates that the reactants could be efficiently oxidized to concomitant chemical products at the anode. The half-cell study shows an onset potential of 1.30 V for benzyl alcohol oxidation reaction (BAOR), 1.36 V for glycerol oxidation reaction (GOR), 1.33 V for ethanol oxidation reaction (EOR), and 1.32 V for urea oxidation reaction (UOR) compared with 1.53 V for WOR. Notably, the hybrid electrolyzer in a full-cell configuration significantly reduces the overall cell voltage at a 20 mA cm(-2) current density by similar to 15% while coupling with the BAOR, EOR, and GOR and similar to 12% with the UOR as the anodic half-cell reaction. Furthermore, the efficiency of hydrogen generation remains unhampered with the types of oxidation reactions (alcohols and urea) occurring at the anode. This work demonstrates the prospects of lowering the overall cell voltage in the case of a water electrolyzer by integrating the hydrogen evolution reaction with suitable organic molecule oxidation.

10aelectrocatalytic oxidation10aenergy conversion10aimidazole mediated10aLayered compounds10awater splitting1 aShilpa, Nagaraju1 aPandikassala, Ajmal1 aKrishnaraj, Perayil1 aWalko, Priyanka, S.1 aDevi, Nandini1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/co-ni-layered-double-hydroxide-electrocatalytic-oxidation-organic-molecules-approach01684nas a2200205 4500008004100000022001400041245011400055210006900169260000800238300001400246490000700260520095000267100002001217700001801237700002401255700002701279700002401306700002101330856012701351 2022 eng d a1359-734500aEnhanced proton conductivity in amino acid based self-assembled non-porous hydrogen-bonded organic frameworks0 aEnhanced proton conductivity in amino acid based selfassembled n cMAY a5972-59750 v583 a

beta-Alaninium oxalate hemihydrate, glycinium oxalate, and L-leucinium oxalate salt-cocrystals as non-porous self-assembled hydrogen-bonded organic frameworks afforded proton conductivity of 2.43 x 10(-2) S cm(-1) (60 degrees C, 95% RH), 3.03 x 10(-2) S cm(-1) (60 degrees C, 95% RH), and 1.19 x 10(-2) S cm(-1) (80 degrees C, 95% RH), respectively. These materials possess an extensive 3-dimensional network of hydrogen bonds in their crystal structures, making them efficient proton conducting membranes. The reduction in conductivity values over 10(-1) S cm(-1) order upon exposure of the samples to a D2O atmosphere in extreme conditions ratified the role of humidity for the conduction of protons. This work explores the relationship between structural features and proton conductivity for the design of proton conducting membranes that are easy to synthesize, eco-friendly, and cheap with potential for futuristic applications.

1 aPramanik, Titas1 aAnand, Ashish1 aPandikassala, Ajmal1 aIllathvalappil, Rajith1 aKurungot, Sreekumar1 aRow, T., N. Guru uhttps://library.ncl.res.in/content/enhanced-proton-conductivity-amino-acid-based-self-assembled-non-porous-hydrogen-bonded01378nas a2200217 4500008004100000022001400041245012800055210006900183260001100252300001400263490000700277520059000284100001800874700002700892700001900919700001800938700002400956700002400980700002501004856013101029 2022 eng d a1523-706000aSynthesis of a highly electron-deficient, water-stable, large ionic box: multielectron accumulation and proton conductivity0 aSynthesis of a highly electrondeficient waterstable large ionic  cAPR 19 a3038-30420 v243 a

pi-acidic boxes exhibiting electron reservoir and proton conduction are unprecedented because of their instability in water. We present the synthesis of one of the strongest electron-deficient ionic boxes showing e(-) uptake as well as proton conductivity. Two large anions fit in the box to form anion-pi interactions and form infinite anion-solvent wires. The box with NO3-center dot center dot center dot water wires confers high proton conductivity and presents the first example that manifests redox and ionic functionality in an organic electron-deficient macrocycle.

1 aShukla, Jyoti1 aIllathvalappil, Rajith1 aKumar, Sharvan1 aChorol, Sonam1 aPandikassala, Ajmal1 aKurungot, Sreekumar1 aMukhopadhyay, Pritam uhttps://library.ncl.res.in/content/synthesis-highly-electron-deficient-water-stable-large-ionic-box-multielectron-accumulation01783nas a2200229 4500008004100000245010400041210006900145260000800214300001500222490000600237520097200243653001901215653001601234653003501250653002601285653003001311100002201341700002401363700002401387700001801411856012401429 2022 eng d00aTuning of oxygen reduction pathways through structural variation in transition metal-doped Ba2In2O50 aTuning of oxygen reduction pathways through structural variation cJAN ae2021011630 v93 aAbstract Oxygen reduction reaction (ORR) can take place either through a two-electron pathway to form H2O2 or through a four-electron pathway to form H2O. Both the reactions are important in the respective fields, viz., H2O2 production as well as fuel cell technology, and rational design of catalysts is mandatory to acquire high energy efficiency in both cases. Here, we report the structure-electrochemical property correlation of a series of perovskite related brownmillerite compounds, Ba2In0.75M0.25O5 (M=Mn/Fe/Co/Ni/Cu), synthesized by solid-state method. On transition metal doping, octahedral distortions were observed, and the highly disordered material tends to follow the 4e transfer mechanism. More symmetrical structures followed the 2e pathway to form H2O2 as the product with high peroxide selectivity. The distortion in the octahedral arrangement can be a descriptor to finetune the selectivity of the catalysts towards the 2e and 4e pathways of ORR.10abrownmillerite10aDescriptors10aElectrochemical H2O2 synthesis10aOctahedral distortion10aoxygen reduction reaction1 aThundiyil, Shibin1 aPandikassala, Ajmal1 aKurungot, Sreekumar1 aDevi, Nandini uhttps://library.ncl.res.in/content/tuning-oxygen-reduction-pathways-through-structural-variation-transition-metal-doped03178nas a2200217 4500008004100000022001400041245013800055210006900193260000900262300001600271490000700287520239300294100002402687700002402711700001902735700002302754700001602777700001802793700002402811856012502835 2022 eng d a2040-336400aUnravelling faradaic electrochemical efficiencies over Fe/Co spinel metal oxides using surface spectroscopy and microscopy techniques0 aUnravelling faradaic electrochemical efficiencies over FeCo spin cNOV  a15928-159410 v143 a

Cobalt and iron metal-based oxide catalysts play a significant role in energy devices. To unravel some interesting parameters, we have synthesized metal oxides of cobalt and iron (i.e. Fe2O3, Co3O4, Co2FeO4 and CoFe2O4), and measured the effect of the valence band structure, morphology, size and defects in the nanoparticles towards the electrocatalytic hydrogen evolution reaction (HER), the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). The compositional variations in the cobalt and iron precursors significantly alter the particle size from 60 to <10 nm and simultaneously the shape of the particles (cubic and spherical). The Tauc plot obtained from the solution phase ultraviolet (UV) spectra of the nanoparticles showed band gaps of 2.2, 2.3, 2.5 and 2.8 eV for Fe2O3, Co3O4, Co2FeO4 and CoFe2O4, respectively. Further, the valence band structure and work function analysis using ultraviolet photoelectron spectroscopy (UPS) and core level X-ray photoelectron spectroscopy (XPS) analyses provided better structural insight into metal oxide catalysts. In the Co3O4 system, the valence band structure favors the HER and Fe2O3 favors the OER. The composites Co2FeO4 and CoFe2O4 show a significant change in their core level (O 1s, Co 2p and Fe 2p spectra) and valence band structure. Co3O4 shows an overpotential of 370 mV against 416 mV for Fe2O3 at a current density of 2 mA cm(-2) for the HER. Similarly, Fe2O3 shows an overpotential of 410 mV against the 435 mV for Co3O4 at a current density of 10 mA cm(-2) for the OER. However, for the ORR, Co3O4 shows 70 mV improvement in the half-wave potential against Fe2O3. The composites (Co2FeO4 and CoFe2O4) display better performance compared to their respective parent oxide systems (i.e., Co3O4 and Fe2O3, respectively) in terms of the ORR half-wave potential, which can be attributed to the presence of the oxygen vacancies over the surface in these systems. This was further corroborated in density functional theory (DFT) simulations, wherein the oxygen vacancy formation on the surface of CoFe2O4(001) was calculated to be significantly lower (similar to 50 kJ mol(-1)) compared to Co3O4 (001). The band diagram of the nanoparticles constructed from the various spectroscopic measurements with work function and band gap provides in-depth understanding of the electrocatalytic process.

1 aKashyap, Varchaswal1 aPandikassala, Ajmal1 aSingla, Gourav1 aKhan, Tuhin, Suvra1 aHaider, Ali1 aVinod, C., P.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/unravelling-faradaic-electrochemical-efficiencies-over-feco-spinel-metal-oxides-using01911nas a2200301 4500008004100000022001400041245007100055210006900126260000900195490000700204520095100211653002301162653001801185653002401203653003801227653002601265653002401291100002801315700001601343700002401359700002601383700001601409700001901425700001601444700002401460700001901484856010601503 2023 eng d a1433-785100aChemically gradient hydrogen-bonded organic framework crystal film0 aChemically gradient hydrogenbonded organic framework crystal fil cJUL 0 v623 a

Hydrogen-bonded organic frameworks (HOFs) are ordered supramolecular solid structures, however, nothing much explored as centimetre-scale self-standing films. The fabrication of such crystals comprising self-supported films is challenging due to the limited flexibility and interaction of the crystals, and therefore studies on two-dimensional macrostructures of HOFs are limited to external supports. Herein, we introduce a novel chemical gradient strategy to fabricate a crystal-deposited HOF film on an in situ-formed covalent organic polymer film (Tam-Bdca-CGHOF). The fabricated film showed versatility in chemical bonding along its thickness from covalent to hydrogen-bonded network. The kinetic-controlled Tam-Bdca-CGHOF showed enhanced proton conductivity (8.3x10(-5) S cm(-1)) compared to its rapid kinetic analogue, Tam-Bdca-COP (2.1x10(-5) S cm(-1)), which signifies the advantage of bonding-engineering in the same system.

10aChemical Gradience10aCrystal Films10aFree-Standing Films10ahydrogen-bonded organic framework10aInterfacial Chemistry10aproton conductivity1 aMohammed, Abdul, Khayum1 aRaya, Jesus1 aPandikassala, Ajmal1 aAddicoat, Matthew, A.1 aGaber, Safa1 aAslam, Mohamed1 aAli, Liaqat1 aKurungot, Sreekumar1 aShetty, Dinesh uhttps://library.ncl.res.in/content/chemically-gradient-hydrogen-bonded-organic-framework-crystal-film02156nas a2200229 4500008004100000022001400041245014800055210006900203260000800272490000600280520131300286653003301599653001501632653003001647653002401677100001801701700002001719700002401739700001501763700002401778856012401802 2023 eng d a2366-748600aPt-anchored-zirconium phosphate nanoplates as high-durable carbon-free oxygen reduction reaction electrocatalyst for PEM fuel cell applications0 aPtanchoredzirconium phosphate nanoplates as highdurable carbonfr cFEB0 v73 a

Commercially available platinum-supported carbon (Pt/C) catalysts are the most widely used oxygen reduction reaction (ORR) electrocatalysts in polymer electrolyte membrane fuel cells (PEMFCs). However, inadequate active triple-phase boundary formation and carbon oxidation in Pt/C during PEMFC operation shorten its lifetime and efficiency. In this direction, a new class of carbon-free electrocatalysts for ORR is prepared by dispersing Pt nanoparticles on ZrP (Zirconium phosphates) nanoplates. In one case (ZrP@Pt), the Pt nanoparticles are found to be closely distributed and completely covering the ZrP nanoplates, whereas in the second case (Pt/ZrP), the Pt nanoparticles selectively restrict dispersion along the edges of the support. ZrP as the support displays an intrinsic proton conductivity of approximate to 0.5 x 10(-4) S cm(-1) at 70 degrees C, with an activation energy (E-a) of 0.19 eV. Pt/ZrP shows better durability after 3000 start-stop cycles. The mass activity of Pt/ZrP is increased by 4.6 times compared to Pt/C, which exhibits a loss in mass activity by 1.37 times. The single-cell level validation of ZrP@Pt, Pt/ZrP, and Pt/C as the electrocatalysts in PEMFC at an operating potential of 0.60 V shows the achievable current densities of 0.600, 0.890, and 0.890 A cm(-2).

10acarbon-free electrocatalysts10afuel cells10aoxygen reduction reaction10azirconium phosphate1 aKumar, Sachin1 aYoyakki, Athira1 aPandikassala, Ajmal1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-anchored-zirconium-phosphate-nanoplates-high-durable-carbon-free-oxygen-reduction01230nas a2200253 4500008004100000022001400041245008600055210006900141260000900210300001400219490000700233520038600240100002800626700002400654700002400678700001600702700002500718700001900743700003000762700002400792700002000816700001900836856012100855 2023 eng d a1359-734500aSalicylaldehydate coordinated two-dimensional-conjugated metal-organic frameworks0 aSalicylaldehydate coordinated twodimensionalconjugated metalorga cFEB  a2608-26110 v593 a

A novel class of copper-based 2D-c-MOF was synthesized from 1,3,5-triformylphloroglucinol using green mechano-chemistry. Herein, metal coordination with the salicylaldehyde functional moiety was explored for the first time in MOFs. Moreover, an intrinsic semiconductive copper-based SA-MOF thin film was fabricated using an in situ salt-free method at room temperature.

1 aMohammed, Abdul, Khayum1 aPena-Sanchez, Pilar1 aPandikassala, Ajmal1 aGaber, Safa1 aAlKhoori, Ayesha, A.1 aSkorjanc, Tina1 aPolychronopoulou, Kyriaki1 aKurungot, Sreekumar1 aGandara, Felipe1 aShetty, Dinesh uhttps://library.ncl.res.in/content/salicylaldehydate-coordinated-two-dimensional-conjugated-metal-organic-frameworks02307nas a2200265 4500008004100000022001400041245015400055210006900209260000800278300001100286490000700297520133900304653002301643653003301666653002201699653003801721653002401759100001801783700001501801700002401816700002401840700002601864700002001890856013101910 2023 eng d a2352-940700aUnlocking the potential of proton conductivity in guanidinium-based ionic covalent organic nanosheets (iCONs) through pore interior functionalization0 aUnlocking the potential of proton conductivity in guanidiniumbas cAUG a1018660 v333 a

Recently, scientists have been exploring the incorporation of proton carriers such as water and phosphoric acid (PA) into the pores and channels of porous materials to enhance proton conduction performance. Ionic covalent organic nanosheets (iCONs) have been identified as promising functional materials due to their inbuilt ionic interfaces, which can facilitate strong interaction with counter ions present inside the pore structure and thus shorten ion transport pathways. However, there is a lack of research related to proton conductivity in iCONs loaded with PA. To address this, we prepared three functionalized guanidinium-based iCONs using a solvothermal condensation reaction between guanidinium amine (TG) and functionalized terephthaldehyde (Da, Dha, and Dma). PA was also incorporated into the iCON structure via ex situ loading to observe its effects on proton conduction performance. The results showed that both the iCONs and PA-iCONs were highly stable in water, organic solvents, acidic and basic media. Amongst these PA-iCONs, one with hydroxyl-functionalization (PA-DhaTG) displayed high proton conductivity at 90 degrees C and 95% relative humidity due to a Grotthuss mechanism for protons. These functionalized guanidinium-based iCONs could prove useful for applications in energy conversion devices.

10achemical stability10aFunctionalized pore interior10aGuanidinium group10aionic covalent organic nanosheets10aproton conductivity1 aKumar, Sushil1 aHu, Jiahui1 aPandikassala, Ajmal1 aKurungot, Sreekumar1 aAddicoat, Matthew, A.1 aSzekely, Gyorgy uhttps://library.ncl.res.in/content/unlocking-potential-proton-conductivity-guanidinium-based-ionic-covalent-organic-nanosheets02683nas a2200217 4500008004100000022001400041245012900055210006900184260000800253490000600261520186200267653003002129653003002159653004302189100002402232700001802256700002802274700001702302700002402319856012202343 2024 eng d a2366-748600aAdvanced 3D network of N-doped graphitic carbon with FeNi alloy embedding for high-performance rechargeable Zn-air batteries0 aAdvanced 3D network of Ndoped graphitic carbon with FeNi alloy e cJUL0 v83 a

Despite the significant progress in Zn-air batteries (ZABs), their widespread use in the rechargeable sector is hindered due to the scarcity of efficient bifunctional oxygen catalysts that can catalyze both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). To address this, an ORR/OER bifunctional electrocatalyst is designed with ultrafine alloyed FeNi nanoparticles encapsulated in a 3D interconnected N- doped carbon network structure, featuring a carbon nitride backbone enclosed in graphitic carbon. The FeNi electrocatalyst (3DFeNiPDC) showed good bifunctional activity toward both ORR and OER in the basic medium with a low overpotential value of 30 mV for ORR and 6 mV for OER compared to its state-of-the-art counterparts Pt/C, and RuO2, respectively. Utilizing 3DFeNiPDC in a rechargeable Zn-air battery (RZAB) yields an open circuit voltage (OCV) of 1.35 V, a maximum power density of 232 mW cm-2, and an energy density of 707 W h kg-1. Additionally, a flexible RZAB employing 3DFeNiPDC demonstrates an OCV of 1.4 V with various bending angles. These finding suggest 3DFeNiPDC as a viable alternative to noble metal-based RZABs, offering superior bifunctional electrocatalytic activity and stability, particularly with its enhanced air-breathing properties facilitating improved operability under practical conditions. The bifunctional electrocatalytic activity of FeNi alloy nanoparticles embedded in a 3D- interconnected N-doped graphitic carbon (3DFeNiPDC) for both oxygen reduction and oxygen evolution is studied. The 3D architecture and core-shell characteristics of FeNi alloy nanoparticles provide better activity and stability for oxygen electrocatalysis. The electrocatalytic activity of 3DFeNiPDC has been exploited for liquid-state and solid-state flexible rechargeable zinc-air batteries. image

10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable flexible zinc-air battery1 aPandikassala, Ajmal1 aKurian, Maria1 aGangadharan, Pranav, K.1 aTorris, Arun1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/advanced-3d-network-n-doped-graphitic-carbon-feni-alloy-embedding-high-performance00991nas a2200301 4500008004100000022001400041245009900055210006900154260000900223490000800232653001100240653001700251653003000268653001600298653001100314100002800325700002400353700002500377700002600402700002100428700001800449700001700467700001200484700002000496700002400516700001900540856013000559 2024 eng d a1385-894700aIron salicylaldehydate conjugated metal-organic framework for quasi solid-state supercapacitor0 aIron salicylaldehydate conjugated metalorganic framework for qua cSEP 0 v49610aCarbon10aconductivity10aELECTROLYTE CONCENTRATION10aperformance10aROBUST1 aMohammed, Abdul, Khayum1 aPandikassala, Ajmal1 aSanchez, Pilar, Pena1 aGaber, Safa, Abdullah1 aCanossa, Stefano1 aKurian, Maria1 aXavier, Gigi1 aHe, Yao1 aGandara, Felipe1 aKurungot, Sreekumar1 aShetty, Dinesh uhttps://library.ncl.res.in/content/iron-salicylaldehydate-conjugated-metal-organic-framework-quasi-solid-state-supercapacitor02684nas a2200205 4500008004100000022001400041245014200055210006900197260000900266300001400275490000700289520191400296100002402210700002002234700002402254700002502278700002402303700002202327856012902349 2024 eng d a0897-475600aRole of nitrogen doping in modulating ruthenium nanocatalysts for enhanced electrochemical hydrogen evolution reaction in alkaline medium0 aRole of nitrogen doping in modulating ruthenium nanocatalysts fo cAPR  a4262-42740 v363 a

Nitrogen doping has become a fundamental approach to enhance the catalytic performance of carbon materials across various applications. The introduction of nitrogen creates defects and active sites, promoting the formation of small metal particles and strengthening the metal-support interaction within carbon materials. However, the challenge lies in developing sustainable and cost-effective methods for synthesizing nitrogen-doped carbon materials. In this study, we present a sustainable approach for the synthesis of ruthenium on nitrogen-doped carbon catalysts (Ru-CCP) using chitosan as a nitrogen and carbon source. Unlike traditional methods, our process avoids the use of additional nitrogen precursors and templates, streamlining the synthesis while using a renewable resource. The synthesized material exhibits an exceptional performance in the electrochemical hydrogen evolution reaction (HER) in alkaline conditions by achieving a current density of 25 mA cm(-2) at an impressively low overpotential of 46 mV, outperforming Pt/C under similar conditions. The detailed studies on structural and electronic properties of the materials using X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) revealed that the remarkable catalytic activity is upheld by the unique interplay between Ru delta+ and surface nitrogen moieties, notably pyridinic and pyrrolic nitrogen. Here, we demonstrate the control of particle size and electronic environment around the metal atom via the interaction of nitrogen and unravel the role of nitrogen doping in tuning the catalytic performance. In addition, this work offers insights into efficient HER catalyst design and emphasizes the potential of biomass-derived materials like chitosan in advancing clean hydrogen production for renewable energy applications.

1 aKorampattu, Lavanya1 aBarik, Sidharth1 aPandikassala, Ajmal1 aUrkude, Rajashri, R.1 aKurungot, Sreekumar1 aDhepe, Paresh, L. uhttps://library.ncl.res.in/content/role-nitrogen-doping-modulating-ruthenium-nanocatalysts-enhanced-electrochemical-hydrogen02589nas a2200325 4500008004100000022001400041245014000055210006900195260000800264490000700272520142200279653002001701653001901721653002801740653002801768653003001796653003901826653001601865653001801881653005001899100002201949700002401971700002701995700002402022700001802046700002602064700001802090700002402108856013102132 2025 eng d a1613-681000aHot injection assisted electronically modulated twin and grain boundary rich sub-2 nm pt3co alloy resistant to phosphate ion for PEMFCs0 aHot injection assisted electronically modulated twin and grain b cMAY0 v213 a

Modulation of the electronic d-band center, structural defects (line defects), and particle size of Pt3Co alloy electrocatalyst have huge significance in elevating its electrochemical oxygen reduction reaction activity. Deviating from traditional high-temperature strategies, the current work focuses on ripening these benefits by implying a simple economically viable hot-injection-assisted modified polyol process. A conclusive control over decrementing particle size starting from 2.7 to 1.3 nm, an increasing degree of strain (twin boundary), and shifting of the d-band center away from the Fermi level are obtained via varying the temperature to which the solution is injected. The catalyst prepared via the injection at 200 degrees C (Pt3Co(1.3 t,g-b)/fVC-200) has delivered an electrochemical surface area of 84 m(2) g(Pt)(-1) with the onset and half-wave potentials of 0.980 and 0.858 V, respectively, versus RHE and a limiting current of -6.0 mA cm(-2) with stability till 20k cycles. In the high-temperature proton exchange membrane fuel cell Pt3Co(1.3 t,g-b)/fVC-200-based cell has outperformed Pt/C rendering 600 mWcm(-2) under H-2-Air compared to 529 mWcm(-2) of Pt/C with 20% lower Pt loading and double the stability due to enhanced resistance toward phosphoric acid for accelerated voltage cycling. A similar enhancement is seen while employing the catalyst for low-temperature fuel cells.

10aelectrocatalyst10agrain boundary10ahot injection synthesis10amodified polyol process10aoxygen reduction reaction10aproton exchange membrane fuel cell10aPt3Co alloy10atwin boundary10avalance band X-ray photoelectron spectroscopy1 aSingh, Mayank, U.1 aJadhav, Swapnil, D.1 aShivankar, Bhavana, R.1 aPandikassala, Ajmal1 aKumar, Yogesh1 aKrishnamurty, Sailaja1 aVinod, C., P.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/hot-injection-assisted-electronically-modulated-twin-and-grain-boundary-rich-sub-2-nm-pt3co02916nas a2200181 4500008004100000022001400041245012700055210006900182260000800251300001600259490000700275520223300282100002402515700002402539700001802563700002402581856012902605 2025 eng d a2050-748800aIn situ engineered triple phase boundary enhancement in 3D structured carbon supported catalyst for high-temperature PEMFC0 aIn situ engineered triple phase boundary enhancement in 3D struc cJUL a21847-218630 v133 a

Enhancing platinum (Pt) utilization in polymer electrolyte membrane fuel cells (PEMFCs) requires optimizing the catalyst support microstructures to expand the triple-phase boundary (TPB). A promising method has been reported here which employs a three-dimensional (3D) catalyst support with an in situ-generated ionomer interface from preadmitted monomer molecules, potentially replacing the traditional Nafion ionomers. The small-sized monomers infiltrate the catalyst's pores, and UV curing polymerizes them into an extended interfacial network within the 3D carbon support. The single-cell analysis of the membrane electrode assemblies (MEAs) in high-temperature PEMFCs (HT-PEMFCs) using phosphoric acid-doped polybenzimidazole (PBI) membranes highlights the effectiveness of this approach. The strategy helps to achieve a current density of 1.06 A cm-2 and 0.49 A cm-2 at 0.60 V in H2-O2 and H2-air feed conditions, respectively. These values represent a significant improvement over the conventional Nafion ionomer-based MEAs, which exhibit current densities of 0.87 A cm-2 and 0.40 A cm-2 under H2-O2 and H2-air feeds, respectively, when utilizing a platinum-supported carbon (Pt/C) catalyst. When Pt nanoparticles are decorated on a high-surface-area, porous 3D interconnected carbon support synthesized via the carbonization of the polydopamine-coated melamine foam (Pt/3DPDC), the conventional Nafion ionomers tend to block the nanopores in the 3D carbon supports, leading to the underutilization of the Pt active sites. In contrast, the in situ ionomer approach enabled the system to deliver 0.93 A cm-2 at 0.60 V H2-O2 feed conditions, which is significantly higher than 0.38 A cm-2 obtained with the Nafion-based ionomers under similar conditions. This approach successfully makes use of the Pt active sites present in the nanopores and tackles the issues of mass transfer and reactant distribution, both of which are essential for expanding fuel cells from single cells to stacks. The exhibited method emphasizes how crucial it is to develop process-friendly electrocatalysts and complementary electrode manufacturing techniques in order to advance the PEMFC performance through a novel scientific path.

1 aPandikassala, Ajmal1 aJadhav, Swapnil, D.1 aKurian, Maria1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/situ-engineered-triple-phase-boundary-enhancement-3d-structured-carbon-supported-catalyst02452nas a2200229 4500008004100000022001400041245013900055210006900194260000800263490000600271520157000277653003001847653003001877653004301907100002401950700002701974700002202001700002402023700002002047700002402067856013102091 2025 eng d a2366-748600aPt-based 3D electrocatalyst with process-friendly features for PEMFCs possessing fast activation and improved mass-transfer properties0 aPtbased 3D electrocatalyst with processfriendly features for PEM cAPR0 v93 a

Polymer-electrolyte-membrane fuel cells (PEMFCs) face the challenges like slow oxygen reduction reaction (ORR) kinetics and limited mass transport at high current densities, which affects their performance. The efficient water removal from the cathode is essential to improve oxygen diffusion. Addressing this, a catalyst is presented with platinum (Pt) nanoparticles distributed within a 3D carbon network (Pt/3DPDC) derived from the polydopamine-coated melamine foam. This unique architecture enhances Pt utilization and water management due to its high porosity and ample free spaces, providing a process-friendly feature for the electrode under PEMFC conditions. The pores and accessible texture of the 3D polydopamine derived carbon (3DPDC) framework facilitate ionomer uptake during the electrode fabrication, extending the active triple-phase boundary and improving the membrane electrode assembly (MEA) performance. The high porosity of Pt/3DPDC is mitigated by adding a small amount of commercial fuel cell catalayst (Pt/C), which maintains the effective catalyst number density per unit area by utilizing the excess porosity of the 3DPDC framework. This controlled interplay of the unique catalyst structure and spatially confined distribution of Pt/C within the Pt/3DPDC framework offers fast activation, reduced electrode flooding, and improved current densities across the operating potential window. This carefully engineered catalyst, designed through bottom-up strategies, is a promising electrocatalyst for practical PEMFC applications.

10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable flexible zinc-air battery1 aPandikassala, Ajmal1 aNadumattuvayil, Varsha1 aSingh, Mayank, U.1 aJadhav, Swapnil, D.1 aYoyakki, Athira1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-based-3d-electrocatalyst-process-friendly-features-pemfcs-possessing-fast-activation-and02981nas a2200277 4500008004100000022001400041245015800055210006900213260000800282300001600290490000700306520197400313653002102287653003202308653002102340653002902361653002202390653003802412100002002450700001802470700002402488700002402512700001802536700002402554856012502578 2025 eng d a2155-543500aA Pt-Based Carbon-Free Cathode with Embedded Oxygen Nanoreservoirs: A Promising Approach for Oxygen Buffering to Aid Oxygen Reduction Reactions of PEMFCs0 aPtBased CarbonFree Cathode with Embedded Oxygen Nanoreservoirs A cNOV a19677-196940 v153 a

For practical applications of proton exchange membrane fuel cells (PEMFCs), the system needs to be operated by employing air in the cathode instead of pure oxygen (O2). This makes it necessary to develop innovative electrode engineering solutions so that the system can function well even in oxygen-lean environments under the realistic working conditions of PEMFCs. Taking this into account, we introduce Pt/SiO2@CeO2-30%, an engineered electrocatalyst with potentially generated oxygen vacancies (Ov), which can immensely contribute toward the enhancement in the O2 availability in oxygen-lean conditions like the air feed conditions, allowing an effective control of the overpotential related to the oxygen reduction reactions (ORRs) at the electrode level. The meticulously crafted Pt-CeO2 interface serves as one of the appreciable structural attributes of the present catalyst, facilitating oxygen spillover toward the Pt environment, aided by the creation of the immense Ov along the nano CeO2 phase of the catalyst. In addition to the benefit of addressing the oxygen-lean conditions and overcoming the limitations of the state-of-the-art catalysts, usage of a noncarbonaceous support like SiO2 to house the Pt and CeO2 nanoparticles has been anticipated to lessen the corrosion problems, a major drawback associated with the carbon-based ORR catalysts. Apart from this, a significant contribution of SiO2 to the self-humidification of the ionomer interface plays a crucial role in enabling the MEA to work under low relative humidity conditions, which can be attributed to an additional benefit of the current composition of the catalyst. The catalyst demonstrated a promising ORR performance with a substantial improvement in H2-air feed circumstances and better corrosion resistance when tested with a membrane electrode assembly (MEA) in a single-cell configuration, illustrating the practical feasibility in a realistic system-level validation.

10acarbon corrosion10acarbon-free electrocatalyst10aoxygen buffering10aoxygen reductionreaction10aoxygen spill over10aprotonexchange membrane fuel cell1 aYoyakki, Athira1 aKumar, Sachin1 aPandikassala, Ajmal1 aJadhav, Swapnil, D.1 aVinod, C., P.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-based-carbon-free-cathode-embedded-oxygen-nanoreservoirs-promising-approach-oxygen02108nas a2200169 4500008004100000022001400041245012400055210006900179260000800248300001600256490000700272520146700279100001801746700002401764700002401788856012601812 2025 eng d a2050-748800aUV-modified polydopamine zincophilic protective layer for durable and alkaline-stable zinc anodes in zinc-air batteries0 aUVmodified polydopamine zincophilic protective layer for durable cNOV a38928-389440 v133 a

Rechargeable zinc-air batteries (ZABs) are promising for flexible energy storage due to their high specific energy, safety, and cost-effectiveness. However, the snags of the zinc (Zn) anode, like ineluctable passivation and dissolution in strongly alkaline electrolytes, limit the discharge and cycling performance of the battery. Electroless plating can be employed to coat the Zn foil with a polydopamine (PDA) layer, leveraging PDA's strong adsorption on the Zn via bidentate bonds. Due to PDA's poor stability in alkaline media, ultraviolet (UV)-induced secondary modifications are conducted to obtain Zn@PDA-UV electrodes with enhanced mechanical and chemical stability. The Zn@PDA-UV layer regulates Zn dendrite growth and suppresses hydrogen evolution and passivation. The zincophilic groups on the Zn@PDA-UV anode suppressed the zincate cross-over, enhancing the recyclability of the ZABs. When paired with commercial catalysts to assemble alkaline ZABs, the battery displayed excellent cycling stability of 75 h. A highly stable anion-conducting polymer electrolyte membrane (PXM) was prepared from the polymer blend of polyvinyl alcohol (PVA), xanthan gum, and METAC monomers to tailor a high-performing flexible ZAB with suppressed zincate crossover. The flexible ZAB, integrating the modified Zn anode and PXM, shows a stable cycling profile under various bending angles, demonstrating excellent mechanical and electrochemical durability.

1 aKurian, Maria1 aPandikassala, Ajmal1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/uv-modified-polydopamine-zincophilic-protective-layer-durable-and-alkaline-stable-zinc02297nas a2200253 4500008004100000245015700041210006900198260000800267300001100275490000600286520134700292653003301639653003001672653003001702653003401732100001801766700001701784700002401801700002001825700002001845700002601865700002401891856012801915 2026 eng d00aElucidating the oxygen electrocatalytic activity of chromium cobalt spinel oxide supported over the spherical carbon for rechargeable zinc-air batteries0 aElucidating the oxygen electrocatalytic activity of chromium cob cMAY ae703360 v93 a

Cr1.5Co1.5O4 spinel nanoparticles supported over 3D spherical carbon (Cr1.5Co1.5O4/C-800) is synthesized as a bifunctional electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for rechargeable zinc air battery (RZAB) applications. The incorporation of Cr into the spinel lattice and the decoration of the active material on a 3D spherical carbon support with intrinsic ORR activity and superior electrical conductivity enable uniform distribution of catalytically active sites, thereby improving bifunctional catalytic activity. The DFT studies were conducted to understand the role of the Cr in modulating the catalytic sites of the active material and to elucidate its effect on tuning the Co sites to enhance the activity. Half-cell studies show that Cr incorporation and spherical carbon support synergistically enhanced catalytic activity, with the Cr1.5Co1.5O4/C-800 catalyst demonstrating an onset potential of 0.93 V (70 mV lower than Pt/C) and an E & half; value of 0.70 V for ORR and an overpotential of 0.369 V at 20 mA cm-2 (eta 20) for OER (0.375 V for the RuO2 catalyst). The catalyst's bifunctional activity was validated in an RZAB, where it outperformed the Pt/C-RuO2 benchmark, delivering superior rate capability and stability and achieving a cycling life exceeding 145 h.

10achromium cobalt spinel oxide10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable zinc-air battery1 aKurian, Maria1 aAmin, Seerat1 aPandikassala, Ajmal1 aManoj, Malavika1 aVijayan, Jubina1 aKrishnamurty, Sailaja1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/elucidating-oxygen-electrocatalytic-activity-chromium-cobalt-spinel-oxide-supported-over