Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
2 results
Search Results
Item 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.Item Structural, dielectric and impedance functionalities of La0.01Cu0.99O nanocrystals(Springer, 2023) Deepapriya, S.; Rodney, J.D.; Udayashankar, N.K.The necessity for materials designed with high and low-K dielectric constant having unique thermal stability has been a prime factor for the continuous development of the microelectronics-based industries. To address this issue, pure and 1% lanthanum (La) substituted copper oxide (CuO) nanoparticles were synthesized through an eco-friendly and time effective co-precipitation route for new unanticipated facts. The thermal effisivity of the material was determined by means of photoacoustic spectroscopy (PAS). The dielectric analysis of the monoclinic structured pure and La doped CuO nanoparticles in the frequency range of 1 Hz–1 MHz for various temperatures was noted, Dielectric constant and loss factor had a declining trend with surge in applied frequency and turned out to be independent of frequency at higher frequencies. The AC conductivity observed has confirmed the semi-conducting nature of the nanoparticle and obeyed Jonscher’s universal law. The temperature-dependant electric relaxation process was revealed using complex impedance spectroscopic studies suggesting non-Debye type behaviour of the material. The electrical activity of the nanoparticles is established for the circuit model devised from the calculated relaxation time constant. The impact of the thermal property and the hopping mechanism in the material with indices of interest is confirmed from the electric modulus. The obtained impedance spectra indicate the effect of lanthanum on the grain boundaries and the higher basicity and electropositive nature of lanthanum on the dielectric relaxation process. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.