@article {43882, title = {Activity tuning of cobalt ferrite nanoparticles anchored on N-doped reduced graphene oxide as a potential oxygen reduction electrocatalyst by Zn substitution in the spinel matrix}, journal = {Chemistry Select}, volume = {2}, year = {2017}, month = {SEP}, pages = {7845-7853}, type = {Article}, abstract = {

Development of highly efficient and durable ORR catalysts by using non-platinum group metals (such as Co, Fe, Mn, and Zn) is a challenging task in the forward path towards the realization of low-cost energy devices in the commercial stream. The present work deals with an effective strategy wherein an efficient Pt-free electrocatalyst for oxygen reduction reaction (ORR) is prepared by stoichiometrically substituting some fraction of Fe with Zn in cobalt ferrite and anchoring these spinel nanoparticles on nitrogen doped reduced graphene oxide (N-rGO). Zn substitution is found to be significantly altering the ratio of Fe2+/Fe3+ in the cobalt ferrite nanocrystal system with a concomitant promotional influence on its electrocatalytic activity towards ORR. The nanoparticle composition with a Co, Fe and Zn molar ratio of 1.0:1.7:0.3, represented by the formula CoFe1.7Zn0.3O4(CFZn(0.3)), supported over N-rGO has shown 10 mV and 20 mV positive shift in the onset and half-wave potentials, respectively, for ORR in 0.1 M KOH in comparison to the nanoparticles of CoFe2O4 supported over N-rGO (CF/N-rGO). The optimum Zn substitution is found to be narrowing down the difference with the state-of-the-art Pt/C for ORR by 100 and 110 mV in terms of the onset and half-wave potentials, respectively. Most significantly, the homemade catalyst is found to be clearly outperforming the Pt catalyst in terms of the limiting current density and electrochemical durability.

}, keywords = {Carbon Nano-fiber, Cathod Catalyst, CoFe2O4, Evolution, Magnetic-properties, Membrane fuel- Cell, Metal-Air Batteries, N-doped graphene, Nanocrystalline, nanocrystals, oxygen reduction reaction, performance, Platinium, solvothermal synthesis, Zn substituted cobalt ferrite}, issn = {2365-6549}, doi = {10.1002/slct.201701684}, author = {Kashyap, Varchaswal and Singh, Santosh K. and Kurungot, Sreekumar} } @article {43870, title = {NiZn double hydroxide nanosheet-anchored nitrogen-doped graphene enriched with the gamma-NiOOH phase as an activity modulated water oxidation electrocatalyst}, journal = {Nanoscale}, volume = {9}, year = {2017}, month = {SEP}, pages = {12590-12600}, type = {Journal Article}, chapter = {12590-12600}, abstract = {

Herein, we report a facile solvothermal process to synthesize an active electrocatalyst for the oxygen evolution reaction (OER) in an alkaline medium by anchoring nanosheets of a NiZn double hydroxide over nitrogen doped reduced graphene oxide after enriching the system with the γ-NiOOH phase. This catalyst possesses a thin, porous and open layered structure, which makes the system more efficient and accessible for a better electrochemical water oxidation reaction. Moreover, we experimentally demonstrated that incorporation of Zn via a single-step solvothermal method provides an easy approach to obtain plenty of exposed γ-NiOOH phases to make the system more viable for OER with a small overpotential of 290 mV at 10 mA cm-2 and a Tafel slope of 44 mV per decade. In addition to this, the oxophilic nature of Zn in the (Zn)Ni-LDH/N-rGO catalyst helps to improve the long-term stability of the whole system. The obtained results open up possibilities for the design of future robust OER electrocatalysts by the use of very cheap and abundant materials like Ni and Zn in place of expensive Ir and Ru in the present commercial electrocatalysts.

}, keywords = {catalysis, Efficient Electrocatalyst, kinetics, Metal, Nickel-Hydroxide, oxide, Oxygen Evolution Reaction, performance, XPS Spectra, zinc}, issn = {2040-3364}, doi = {10.1039/c7nr02225e}, author = {Nadeema, Ayasha and Dhavale, Vishal M. and Kurungot, Sreekumar} } @article {49251, title = {Iron salicylaldehydate conjugated metal-organic framework for quasi solid-state supercapacitor}, journal = {CHEMICAL ENGINEERING JOURNAL}, volume = {496}, year = {2024}, month = {SEP }, type = {Journal Article}, keywords = {Carbon, conductivity, ELECTROLYTE CONCENTRATION, performance, ROBUST}, issn = {1385-8947}, doi = {10.1016/j.cej.2024.153589}, author = {Mohammed, Abdul Khayum and Pandikassala, Ajmal and Sanchez, Pilar Pena and Gaber, Safa Abdullah and Canossa, Stefano and Kurian, Maria and Xavier, Gigi and He, Yao and Gandara, Felipe and Kurungot, Sreekumar and Shetty, Dinesh} }