Browsing by Author "Perumal, S."

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Boosting overall electrochemical water splitting via rare earth doped cupric oxide nanoparticles obtained by co-precipitation technique
(Elsevier Ltd, 2022) Rodney, J.D.; Deepapriya, S.; Jerome das, S.J.; Robinson, M.C.; Perumal, S.; Sadhana, S.; Periyasamy, P.; Jung, H.; Justin Raj, C.J.
The development of electrocatalyst based on nonprecious metals has been a persistent issue as electrochemical water splitting requires electrocatalyst with advanced activity and stability. Further, the electrocatalyst must require low overpotential above the standard potential (>1.23 V) of water splitting to produce hydrogen. This study presents the facile co-precipitation derived rare earth dysprosium (Dy) doped cupric oxide nanoparticles (Cu1−xDyxO) as a non-noble transition metal oxide nanoparticle. The 3 % Dy doped CuO (3 % Dy/CuO) and 1 % Dy doped CuO (1 % Dy/CuO) electrocatalysts showed excellent Oxygen Evolution Reaction (OER) at 1.55 V vs RHE and Hydrogen Evolution Reaction (HER) at − 0.036 V vs RHE in aqueous 1 M KOH aqueous electrolyte to attain the benchmark current density (10 mA cm−2). The stability of the driven electrocatalyst in a bi-functional electrocatalytic setup was monitored for 24 h and was found to be exhibiting a cell voltage of about 2.1 V at 30 mA cm−2 constant current density. Further, the retention capability of the electrode was observed to be 99 % with a very minimal loss. This study hugely suggests the promising consequence of doping rare earth onto a non-precious metal oxide-based electrocatalyst, making it a highly effective bifunctional material for water splitting. © 2022 Elsevier B.V.
Electrocatalytic synergies of melt-quenched Ni-Sn-Se-Te nanoalloy for direct seawater electrolysis
(Elsevier B.V., 2024) Rodney, J.D.; Joshi, S.; Ray, S.; Rao, L.; Deepapriya, S.; Carva, K.; Badekai Ramachandra, B.R.; Udayashankar, N.K.; Perumal, S.; Sadhana, S.; Justin Raj, C.J.; Kim, B.C.
The study focuses on the development of binary nanoalloys based on metal dichalcogenides (Sn30Se70, Ni30Te70) and quaternary nanoalloy (Ni15Sn15Se35Te35) using the melt quenching technique. The nanoalloys show extensive water splitting in fresh and real seawater. Sn30Se70-coated nickel foam achieved a benchmark current density of 349 mV for the oxygen evolution reaction (OER), while Ni15Sn15Se35Te35-coated nickel foam (NF) required only 185 mV for the hydrogen evolution reaction (HER) in 1 M KOH. The study also shows that a two-electrode system can achieve sustained total water splitting at higher current densities (1 A.cm?2). Modification with a CuSx layer over NF at the OER end facilitated faster kinetics and mitigated chlorine corrosion enabling direct seawater splitting at 1.26 V. Continuous direct splitting of seawater at 100 mA cm?2 for 120 h required only 1.88 V, showing an efficiency of 92.9 % for H2 production in real seawater. © 2024 Elsevier B.V.
New hybrid semiconducting CdSe and Fe doped CdSe quantum dots based electrochemical capacitors
(Elsevier Ltd, 2022) Premanand, G.; Sridevi, D.V.; Perumal, S.; Maiyalagan, T.; Rodney, J.D.; Ramesh, V.
In this study, pure and Fe-doped CdSe (Fe@CdSe) quantum dots (QDs) in various concentrations have been prepared via the chemical co-precipitation method. The PXRD, FT-IR, UV–vis spectroscopy, and HR-TEM micrographs have been utilized to confirm the structural, optical, and morphological features of as-synthesized QDs. The optical bandgap values of pure and Fe@CdSe QDs have been found to vary from 2.12 eV to 1.82 eV, as determined by the Tauc relation, and the absorption spectrum of pure and Fe@CdSe QDs exhibits a blue shift compared to the bulk CdSe. Moreover, three-electrode configuration systems have been employed to characterize the electrochemical properties of pure and Fe@CdSe QDs. Notably, the areal capacitance of pure CdSe is 47 mFcm−2, which considerably increases to ∼73 mFcm−2 for 6 mol.% Fe@CdSe QDs QDs at a scan rate of 5 mVs−1. © 2022 Elsevier B.V.