Sathya Narayanan Jagadeesan

All Publications

• Electrochemical Reduction Pathways from Goethite to Green Iron in Alkaline Solution with Silicate Additive ACS SUSTAINABLE CHEMISTRY & ENGINEERING Arumugam, D., Zhou, T., Jagadeesan, S., Pidathala, R., Zhang, L., Abeykoon, A., Kwon, G., Olds, D., Narayanan, B., Teng, X. 2025

  View details for DOI 10.1021/acssuschemeng.4c08451

  View details for Web of Science ID 001418148700001

• Unlocking High Capacity and Reversible Alkaline Iron Redox Using Silicate-Sodium Hydroxide Hybrid Electrolytes. ChemSusChem Jagadeesan, S. N., Guo, F., Pidathala, R. T., Abeykoon, A. M., Kwon, G., Olds, D., Narayanan, B., Teng, X. 2024; 17 (19): e202400050

  Abstract

  Alkaline iron (Fe) batteries are attractive due to the high abundance, low cost, and multiple valent states of Fe but show limited columbic efficiency and storage capacity when forming electrochemically inert Fe3O4 on discharging and parasitic H2 on charging. Herein, sodium silicate is found to promote Fe(OH)2/FeOOH against Fe(OH)2/Fe3O4 conversions. Electrochemical experiments, operando X-ray characterization, and atomistic simulations reveal that improved Fe(OH)2/FeOOH conversion originates from (i) strong interaction between sodium silicate and iron oxide and (ii) silicate-induced strengthening of hydrogen-bond networks in electrolytes that inhibits water transport. Furthermore, the silicate additive suppresses hydrogen evolution by impairing energetics of water dissociation and hydroxyl de-sorption on iron surfaces. This new silicate-assisted redox chemistry mitigates H2 and Fe3O4 formation, improving storage capacity (199 mAh g-1 in half-cells) and coulombic efficiency (94 % after 400 full-cell cycles), paving a path to realizing green battery systems built from earth-abundant materials.

  View details for DOI 10.1002/cssc.202400050

  View details for PubMedID 38898597

• Enhanced Urea Oxidation Electrocatalytic Activity by Synergistic Cobalt and Nickel Mixed Oxides. The journal of physical chemistry letters Zhou, T., Jagadeesan, S. N., Zhang, L., Deskins, N. A., Teng, X. 2024; 15 (1): 81-89

  Abstract

  Exploring reactive and selective Ni-based electrocatalysts for the urea oxidation reaction (UOR) is crucial for developing urea-related energy conversion technologies. Herein, synergistic interactions in Ni/Co mixed oxides/hydroxides enhanced the UOR with low onset potential, fast reaction kinetics, and good selectivity against the oxygen evolution reaction (OER). Our electrochemical measurements and theoretical calculations signified the collaborative interaction of Ni/Co mixed oxide/hydroxide heterostructures to enhance UOR activity. Our results showed that Ni3+ species, formed at high anodic potential, produced a high anodic current primarily from unwanted OER. Instead, the Ni/Co heterostructures with dominant Ni2+ and Co3+ species remained stable at low anodic potential and exhibited anodic current exclusively attributed to UOR. This work highlights the importance of tuning valence charges for designing high-performance and selective UOR electrocatalysts to benefit the environmental remediation of urea runoff and enable urea electrolysis for hydrogen production by replacing conventional OER with UOR at the anode.

  View details for DOI 10.1021/acs.jpclett.3c03257

  View details for PubMedID 38133934

• Chloride Insertion Enhances the Electrochemical Oxidation of Iron Hydroxide Double-Layer Hydroxide into Oxyhydroxide in Alkaline Iron Batteries CHEMISTRY OF MATERIALS Jagadeesan, S., Barbosa, G. D., Guo, F., Zhang, L., Abeykoon, A., Kwon, G., Olds, D., Turner, C., Teng, X. 2023; 35 (16): 6517-6526

  View details for DOI 10.1021/acs.chemmater.3c01496

  View details for Web of Science ID 001042145400001

• Revitalizing Iron Redox by Anion-Insertion-Assisted Ferro- and Ferri-Hydroxides Conversion at Low Alkalinity. Journal of the American Chemical Society Guo, F., Jagadeesan, S. N., Pidathala, R. T., Kim, S., Shan, X., Deskins, N. A., Abeykoon, A. M., Kwon, G., Olds, D., Narayanan, B., Teng, X. 2022; 144 (27): 11938-11942

  Abstract

  Iron hydroxides are desirable alkaline battery electrodes for low cost and environmental beneficence. However, hydrogen evolution on charging and Fe3O4 formation on discharging cause low storage capacity and poor cycling life. We report that green rust (GR) (Fe2+4Fe3+2 (HO-)12SO4), formed via sulfate insertion, promotes Fe(OH)2/FeOOH conversion and shows a discharge capacity of ∼211 mAh g-1 in half-cells and Coulombic efficiency of 93% after 300 cycles in full-cells. Theoretical calculations show that Fe(OH)2/FeOOH conversion is facilitated by intercalated sulfate anions. Classical molecular dynamics simulations reveal that electrolyte alkalinity strongly impacts the energetics of sulfate solvation, and low alkalinity ensures fast transport of sulfate ions. Anion-insertion-assisted Fe(OH)2/FeOOH conversion, also achieved with Cl- ion, paves a pathway toward efficient utilization of Fe-based electrodes for sustainable applications.

  View details for DOI 10.1021/jacs.2c03113

  View details for PubMedID 35699519

• Advanced Cu3Sn and Selenized Cu3Sn@Cu Foam as Electrocatalysts for Water Oxidation under Alkaline and Near-Neutral Conditions. Inorganic chemistry Karthick, K., Anantharaj, S., Patchaiammal, S., Jagadeesan, S. N., Kumar, P., Ede, S. R., Pattanayak, D. K., Kundu, S. 2019; 58 (14): 9490-9499

  Abstract

  Water electrolysis is a field growing rapidly to replace the limited fossil fuels for harvesting energy in future. In searching of non-noble and advanced electrocatalysts for the oxygen evolution reaction (OER), here we highlight a new and advanced catalyst, selenized Cu3Sn@Cu foam, with overwhelming activity for OER under both alkaline (1 M KOH) and near-neutral (1 M NaHCO3) conditions. The catalysts were prepared by a double hydrothermal treatment where Cu3Sn is first formed which further underwent for second hydrothermal condition for selenization. For comparison, Cu7Se4@Cu foam was prepared by a hydrothermal treatment under the same protocol. The as-formed Cu3Sn@Cu foam, selenized Cu3Sn@Cu foam, and Cu7Se4@Cu foam were utilized as electrocatalysts and showed their potentiality in terms of activity and stability. In 1 M KOH, for attaining the benchmarking current density of 50 mA cm-2, selenized Cu3Sn@Cu foam required a low overpotential of 384 mV and increased charge transfer kinetics with a lower Tafel slope value of 177 mV/dec comparing Cu3Sn@Cu foam, Cu7Se4@Cu foam, and pristine Cu foam. Furthermore, potentiostatic analysis (PSTAT) was carried out for 40 h for selenized Cu3Sn@Cu foam and with minimum degradation in activity assured the long-term application for hydrogen generation. Similarly, under neutral condition selenized Cu3Sn@Cu foam also delivered better activity trend at higher overpotentials in comparison with others. Therefore, the assistance of both Sn and Se in Cu foam ensured better activity and stability in comparison with only selenized Cu foam. With these possible outcomes, it can also be combined with other active, non-noble elements for enriched hydrogen generation in future.

  View details for DOI 10.1021/acs.inorgchem.9b01467

  View details for PubMedID 31247824

• Evaluating DNA Derived and Hydrothermally Aided Cobalt Selenide Catalysts for Electrocatalytic Water Oxidation. Inorganic chemistry Karthick, K., Jagadeesan, S. N., Kumar, P., Patchaiammal, S., Kundu, S. 2019; 58 (10): 6877-6884

  Abstract

  Electrocatalysts with engaging oxygen evolution reaction (OER) activity with lesser overpotentials are highly desired to have increased cell efficiency. In this work, cobalt selenide catalysts were prepared utilizing both wet-chemical route (CoSe and CoSe-DNA) and hydrothermal route (Co0.85Se-hyd). In wet-chemical route, cobalt selenide is prepared with DNA (CoSe-DNA) and without DNA (CoSe). The morphological results in the wet-chemical route had given a clear picture that, with the assistance of DNA, cobalt selenide had formed as nanochains with particle size below 5 nm, while it agglomerated in the absence of DNA. The morphology was nano networks in the hydrothermally assisted synthesis. These catalysts were analyzed for OER activity in 1 M KOH. The overpotentials required at a current density of 10 mA cm-2 were 352, 382, and 383 mV for Co0.85Se-hyd, CoSe, and CoSe-DNA catalysts, respectively. The Tafel slope value was lowest for Co0.85Se-hyd (65 mV/dec) compared to CoSe-DNA (71 mV/dec) and CoSe (80 mV/dec). The chronoamperometry test was studied for 24 h at a potential of 394 mV for Co0.85Se-hyd and was found to be stable with a smaller decrease in activity. From the OER study, it is clear that Co0.85Se was found to be superior to others. This kind of related study can be useful to design the catalyst with increased efficiency by varying the method of preparation.

  View details for DOI 10.1021/acs.inorgchem.9b00354

  View details for PubMedID 31070905