Mechanism of electrochemical oxidation of nitroxide radicals in ethaline deep eutectic Solvent Nora A. Shaheen, Mahesh Ijjada, Miomir B. Vukmirovic, Rohan Akolkar Journal of the Electrochemical Society, 2020 Deep eutectic solvents (DESs) are emerging as promising electrolytes for electrochemical energy storage applications. Electroactive nitroxide-radical-containing organics can be dissolved in DESs to facilitate redox reactions; however, mechanistic know-how of their charge transfer kinetics at the electrode surface is rather limited. Here, we investigate the mechanism underlying the electrochemical oxidation of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy-TEMPO). Using polarization measurements on a platinum rotating disk electrode and micro-electrode, we show that the anodic charge transfer coefficient ( α ) for one-electron transfer oxidations of TEMPO and 4-hydroxy-TEMPO approaches 0.9 in DES as well as in aqueous electrolytes, i.e., a significant deviation from α ≈ 0.5 expected for symmetric redox behavior. To explain this observation, a two-step oxidation mechanism is proposed wherein the nitroxide-containing species undergo fast charge transfer at an electrode surface followed by slow rate-limiting desorption of the adsorbed oxidized species. Numerical simulations are reported to characterize how the proposed two-step mechanism manifests in transient cyclic voltammetry behavior of the 4-hydroxy-TEMPO oxidation reaction, and good agreement with experiments is noted.
Scale-Up Process of Core@Shell Monolayer Catalyst without Active Potential Control through Electroless Underpotential Deposition Galvanic Replacement Ijjada Mahesh, A. Sarkar Chemistryselect, 2018 Core@shell monolayer catalysts have dual advantages in electrocatalysis, cost of the catalyst is minimized by depositing expensive metal as a monolayer shell and the catalytic activity can be enhanced by selecting an appropriate core metal. In this communication, a novel chemically assisted underpotential deposition process to fabricate core@shell monolayer nanoparticles in bulk scale has been introduced. Ag(shell)@Pd(core)/C nanoparticles have been prepared by this electroless underpotential deposition method. The thickness of the Ag shell has been calculated as one atomic layer from XPS analysis. Core‐shell structure of nanoparticles has been confirmed by STEM characterization. Further, Pt(shell)@Pd(core)/C nanoparticles have been engineered from Ag@Pd/C nanoparticles by Galvanic replacement of Ag by Pt. This Pt@Pd/C electrocatalyst has been tested for formic acid oxidation.
Exploring the Feasibility of Hydrogen-Driven Chemical Desalination through Redox-Mediated Salt Ion Capture A Tiwari, A Pratap, VJ Akash, P Upadhyay, S Chakma, I Mahesh ACS Sustainable Resource Management , 2026 2026
Tungsten-modified MXene-integrated Spinel Oxides as High-Performance and Stable Catalysts for Water/Seawater Oxidation D Tanwar, PV Raja, P Vishnu, M Ijjada Journal of Materials Chemistry A , 2026 2026
Dual function of phosphate buffer in untreated seawater electrolysis: boosting oxygen evolution reaction efficiency and inhibiting cathode scaling PV Raja, I Mahesh Sustainable Energy & Fuels 10 (6), 1535-1546 , 2026 2026
Mechanistic understanding of origin of selectivity for oxygen evolution reaction in untreated natural seawater oxidation: Theoretical and experimental insights IM PV Raja, DR Kanchan, A Banerjee, A Joshy, R Sankannavar International Journal of Hydrogen Energy 200, 152946 , 2026 2026 Citations: 2
Natural Seawater Electrolyte Enables CO2 Reduction Selectivity Transition from C1 to C2 Alcohol on Metal Phosphate Catalysts and Suppression of Cathode Scaling with Buffering … S Katre, T Panigrahi, PV Raja, I Mahesh ChemRxiv 2025 (1231) , 2025 2025
Electrostatic-Electrochemical Coupling Enables Energy Storage and Electrosynthesis of Nano-catalysts in Charged Electrolytes PV Raja, P Vishnu, V Kumar, A Chandel, A Sarkar, M Ijjada chemrxiv.org , 2025 2025
Hydrogen Production from Low-Grade Water Electrolysis to Contribute to Sustainable Development Goals 6 and 7: Challenges and Opportunities P Vishnu, D Tanwar, M Ijjada chemrxiv.org , 2025 2025 Citations: 1
Correction to “Hydrated Electrocatalysis: To Boost the Selectivity for the Oxygen Evolution Reaction in Seawater Electrolysis” PV Raja, P Vishnu, TK Panigrahi, R Sankannavar, SP Vangala, I Mahesh The Journal of Physical Chemistry C 129 (4), 2288-2289 , 2025 2025
Hydrated electrocatalysis: to boost the selectivity for the oxygen evolution reaction in seawater electrolysis PV Raja, P Vishnu, TK Panigrahi, R Sankannavar, SP Vangala, I Mahesh The Journal of Physical Chemistry C 129 (1), 262-270 , 2024 2024 Citations: 4
Scalable Production of Monolayer Shell (Pt)@ Core (Pd) Nanoparticles by Electroless Cu UPD for Oxygen Reduction Reaction I Mahesh, A Sarkar Electrocatalysis, 1-10 , 2021 2021 Citations: 4
Mechanism Underlying Electron-Transfer Reactions Involving TEMPO and 4-Hydroxy-TEMPO in Deep Eutectic Solvents M Ijjada, NA Shaheen, MB Vukmirovic, R Akolkar Electrochemical Society Meeting Abstracts prime2020, 2683-2683 , 2020 2020
Mechanism of electrochemical oxidation of nitroxide radicals in ethaline deep eutectic solvent NA Shaheen, M Ijjada, MB Vukmirovic, R Akolkar Journal of The Electrochemical Society 167 (14), 143505 , 2020 2020 Citations: 19
Process for the Synthesis of Monolayer Core- Shell Catalyst IM A. Sarkar IN Patent 338,717 , 2020 2020
Hysteresis effects and roughness suppression efficacy of polyethylenimine additive in Cu electrodeposition in ethaline NA Shaheen, I Mahesh, MB Vukmirovic, R Akolkar Electrochemistry Communications 115, 106721 , 2020 2020 Citations: 7
Electrolyte Additives for Controlling Roughness of Copper Electrodeposits Formed in Deep Eutectic Solvents NA Shaheen, M Ijjada, MB Vukmirovic, R Akolkar Electrochemical Society Meeting Abstracts 237, 1206-1206 , 2020 2020
Nano-structured palladium impregnate graphitic carbon nitride composite for efficient hydrogen gas sensing A Ibrahim, UB Memon, SP Duttagupta, I Mahesh, RKS Raman, A Sarkar, ... International Journal of Hydrogen Energy 45 (17), 10623-10636 , 2020 2020 Citations: 59
Scale‐Up Process of Core@ Shell Monolayer Catalyst without Active Potential Control through Electroless Underpotential Deposition Galvanic Replacement I Mahesh, A Sarkar ChemistrySelect 3 (41), 11622-11626 , 2018 2018 Citations: 3
Self-restraining electroless deposition for shell@ core particles and influence of lattice parameter on the ORR activity of Pt (Shell)@ Pd (Core)/C electrocatalyst I Mahesh, A Sarkar The Journal of Physical Chemistry C 122 (17), 9283-9291 , 2018 2018 Citations: 11
Efficient electrooxidation of ethanol on Bi@ Pt/C nanoparticles:(i) Effect of monolayer Bi deposition on specific sites of Pt nanoparticle (ii) Calculation of average number of … I Mahesh, R Jaithaliya, A Sarkar Electrochimica Acta 258, 933-941 , 2017 2017 Citations: 8
Electrochemical Study of Oxygen Reduction on a Carbon‐Supported Core–Shell Platinum–Gold Electrocatalyst with Tuneable Gold Surface Composition I Mahesh, A Sarkar ChemElectroChem 3 (5), 836-845 , 2016 2016 Citations: 6
MOST CITED SCHOLAR PUBLICATIONS
Nano-structured palladium impregnate graphitic carbon nitride composite for efficient hydrogen gas sensing A Ibrahim, UB Memon, SP Duttagupta, I Mahesh, RKS Raman, A Sarkar, ... International Journal of Hydrogen Energy 45 (17), 10623-10636 , 2020 2020 Citations: 59
Mechanism of electrochemical oxidation of nitroxide radicals in ethaline deep eutectic solvent NA Shaheen, M Ijjada, MB Vukmirovic, R Akolkar Journal of The Electrochemical Society 167 (14), 143505 , 2020 2020 Citations: 19
Self-restraining electroless deposition for shell@ core particles and influence of lattice parameter on the ORR activity of Pt (Shell)@ Pd (Core)/C electrocatalyst I Mahesh, A Sarkar The Journal of Physical Chemistry C 122 (17), 9283-9291 , 2018 2018 Citations: 11
Efficient electrooxidation of ethanol on Bi@ Pt/C nanoparticles:(i) Effect of monolayer Bi deposition on specific sites of Pt nanoparticle (ii) Calculation of average number of … I Mahesh, R Jaithaliya, A Sarkar Electrochimica Acta 258, 933-941 , 2017 2017 Citations: 8
Hysteresis effects and roughness suppression efficacy of polyethylenimine additive in Cu electrodeposition in ethaline NA Shaheen, I Mahesh, MB Vukmirovic, R Akolkar Electrochemistry Communications 115, 106721 , 2020 2020 Citations: 7
Electrochemical Study of Oxygen Reduction on a Carbon‐Supported Core–Shell Platinum–Gold Electrocatalyst with Tuneable Gold Surface Composition I Mahesh, A Sarkar ChemElectroChem 3 (5), 836-845 , 2016 2016 Citations: 6
Hydrated electrocatalysis: to boost the selectivity for the oxygen evolution reaction in seawater electrolysis PV Raja, P Vishnu, TK Panigrahi, R Sankannavar, SP Vangala, I Mahesh The Journal of Physical Chemistry C 129 (1), 262-270 , 2024 2024 Citations: 4
Scalable Production of Monolayer Shell (Pt)@ Core (Pd) Nanoparticles by Electroless Cu UPD for Oxygen Reduction Reaction I Mahesh, A Sarkar Electrocatalysis, 1-10 , 2021 2021 Citations: 4
Structure of micelles in re-entrant phase of SDS/Al(NO 3 ) 3 solutions R Nadaf, M Ijjada, J Narayanan, B Kutty, VK Aswal, JR Bellare, PS Goyal Solid State Physics 1512 (1), 118-119 , 2013 2013 Citations: 4
Scale‐Up Process of Core@ Shell Monolayer Catalyst without Active Potential Control through Electroless Underpotential Deposition Galvanic Replacement I Mahesh, A Sarkar ChemistrySelect 3 (41), 11622-11626 , 2018 2018 Citations: 3
Mechanistic understanding of origin of selectivity for oxygen evolution reaction in untreated natural seawater oxidation: Theoretical and experimental insights IM PV Raja, DR Kanchan, A Banerjee, A Joshy, R Sankannavar International Journal of Hydrogen Energy 200, 152946 , 2026 2026 Citations: 2
Hydrogen Production from Low-Grade Water Electrolysis to Contribute to Sustainable Development Goals 6 and 7: Challenges and Opportunities P Vishnu, D Tanwar, M Ijjada chemrxiv.org , 2025 2025 Citations: 1
Exploring the Feasibility of Hydrogen-Driven Chemical Desalination through Redox-Mediated Salt Ion Capture A Tiwari, A Pratap, VJ Akash, P Upadhyay, S Chakma, I Mahesh ACS Sustainable Resource Management , 2026 2026
Tungsten-modified MXene-integrated Spinel Oxides as High-Performance and Stable Catalysts for Water/Seawater Oxidation D Tanwar, PV Raja, P Vishnu, M Ijjada Journal of Materials Chemistry A , 2026 2026
Dual function of phosphate buffer in untreated seawater electrolysis: boosting oxygen evolution reaction efficiency and inhibiting cathode scaling PV Raja, I Mahesh Sustainable Energy & Fuels 10 (6), 1535-1546 , 2026 2026
Natural Seawater Electrolyte Enables CO2 Reduction Selectivity Transition from C1 to C2 Alcohol on Metal Phosphate Catalysts and Suppression of Cathode Scaling with Buffering … S Katre, T Panigrahi, PV Raja, I Mahesh ChemRxiv 2025 (1231) , 2025 2025
Electrostatic-Electrochemical Coupling Enables Energy Storage and Electrosynthesis of Nano-catalysts in Charged Electrolytes PV Raja, P Vishnu, V Kumar, A Chandel, A Sarkar, M Ijjada chemrxiv.org , 2025 2025
Correction to “Hydrated Electrocatalysis: To Boost the Selectivity for the Oxygen Evolution Reaction in Seawater Electrolysis” PV Raja, P Vishnu, TK Panigrahi, R Sankannavar, SP Vangala, I Mahesh The Journal of Physical Chemistry C 129 (4), 2288-2289 , 2025 2025
Mechanism Underlying Electron-Transfer Reactions Involving TEMPO and 4-Hydroxy-TEMPO in Deep Eutectic Solvents M Ijjada, NA Shaheen, MB Vukmirovic, R Akolkar Electrochemical Society Meeting Abstracts prime2020, 2683-2683 , 2020 2020
Process for the Synthesis of Monolayer Core- Shell Catalyst IM A. Sarkar IN Patent 338,717 , 2020 2020
