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Item Unveiling the Versatile Applications of Cobalt Oxide-Embedded Nitrogen-Doped Porous Graphene for Enhanced Energy Storage and Simultaneous Determination of Ascorbic Acid, Dopamine and Uric Acid(Institute of Physics, 2024) Agadi, N.P.; Hegde, S.S.; Teradal, N.L.; Badekai Ramachandra, B.R.; Seetharamappa, J.The advancement of electrode materials is essential for addressing the energy and biomedical challenges. A multi-functional approach was employed to create a new electrode material of cobalt oxide-embedded nitrogen-doped porous graphene (Co3O4@NpG) for sensing and energy storage applications. In the present study, we have fabricated a new electrochemical sensing platform based on Co3O4@NpG. The sensing performance and selective detection capability of the demonstrated sensor was optimized and tested by determining dopamine (DA), uric acid (UA), and ascorbic acid (AA) simultaneously in analyte fortified biological samples. The sensing response is noticed to be linearly dependent upon the concentration of AA, DA, and UA in the range of 0.1-450, 0.1-502, and 0.2-396 μM, respectively. This material also showed good electrochemical energy storage performance when assessed as a supercapacitor electrode. The Co3O4@NpG electrode material showcased a remarkable specific capacitance of 314.58 Fg−1, an energy density of 10.06 Wh kg−1 at a power density of 240 Wkg−1 at 0.5 Ag−1, in a 6 M KOH electrolyte, along with excellent long-term cycling stability. Hence, the material Co3O4@NpG stands out as a promising multifunctional electrode candidate, excelling in the precise simultaneous detection of critical biomolecules besides exhibiting superior energy storage performance. © 2024 The Electrochemical Society (“ECS”). Published on behalf of ECS by IOP Publishing Limited. All rights, including for text and data mining, AI training, and similar technologies, are reserved.Item Electrochemical performance and structural evolution of spray pyrolyzed Mn3O4 thin films in different aqueous electrolytes: effect of anions and cations(Royal Society of Chemistry, 2024) Adoor, P.; Hegde, S.S.; Badekai Ramachandra, B.R.; George, S.D.; Raviprakash, R.This work presents the impact of cycling in different cationic and anionic aqueous electrolytes on the electrochemical storage performance of the Mn3O4 thin film electrode prepared using the chemical pyrolysis method. Studies on the as-deposited electrode confirmed the formation of Mn3O4 phase. Extensive electrochemical analysis was performed using Na2SO4, NaCl, Li2SO4, K2SO4, and MgSO4 electrolytes to examine the influence of cations and anions on charge storage behaviour. Considerable changes were observed in the specific capacitances owing to different ionic sizes as well as hydrated ionic radius of the electrolyte ions. Accordingly, the electrode unveiled a good performance showing a specific capacitance of around 187 F g−1 at 0.5 A g−1 in K2SO4 electrolyte. Further, the electrode properties are examined after 500 CV cycles to trace the changes in the structural and morphological properties. X-ray diffraction (XRD) and Raman spectroscopic studies illustrate a partial phase transformation of electrodes from Mn3O4 to MnO2 irrespective of the electrolytes. These results are further corroborated with X-ray photoelectron spectroscopic (XPS) analysis where there was an increment in the oxidation state of manganese. It has been observed that the surface properties were significantly changed with cycling, as manifested by the wettability studies of the electrodes. The obtained results brings out the significance of electrolyte ions on the charge storage characteristics of Mn3O4 thin film electrodes in light of their possible application in electrochemical capacitors. © 2024 The Royal Society of Chemistry.Item Unveiling the mass-loading effect on the electrochemical performance of Mn3O4 thin film electrodes: a combined computational and experimental study(Institute of Physics, 2024) Pramitha, A.; Hegde, S.S.; Badekai Ramachandra, B.R.; Yadav K, C.; Chakraborty, S.; Ravikumar, A.; George, S.D.; Sudhakar, Y.N.; Raviprakash, Y.The remarkable storage performance of manganese oxide (Mn3O4) makes it an appealing option for use as electrodes in electrochemical capacitors. However, the storage kinetics were significantly influenced by the mass loading of the electrode. Herein, we have inspected the dependency of mass loading on the storage performance of the spray pyrolyzed Mn3O4 thin film electrodes along with the correlation of structural and morphological characteristics. X-ray diffraction and Raman spectroscopic studies proven the formation of spinel Mn3O4 with a tetragonal structure. Morphological analysis revealed that all films exhibited fibrous structures with interconnected patterns at higher mass loadings. Moreover, the surface roughness and wettability of the electrode surface were influenced by variations in mass loading. Notably, thin-film electrode with a mass loading of 0.4 mg cm?2 exhibited the highest specific capacitance value of 168 F g?1 at 5 mV s?1 in a three-electrode system. Further, electrochemical impedance spectroscopic studies showed that there were noticeable changes in the capacitive behaviour of the electrode with respect to variations in mass loading. Moreover, the Dunn approach was employed to differentiate the underlying storage mechanism of the Mn3O4 electrode. Additionally, first-principles Density Functional Theory (DFT) studies were carried out in connection with the experimental study to comprehend the structure and electronic band structure of Mn3O4. This study underscores the critical importance of mass loading for enhancing the storage performance of Mn3O4 thin-film electrodes. © 2024 The Author(s). Published by IOP Publishing Ltd.Item Electrodeposited CoMnS/NiCo2S4 nanocomposite for high performance supercapacitors(Elsevier Ltd, 2024) Mascarenhas, F.J.; Rodney, J.D.; Rao, L.; Kim, B.C.; Badekai Ramachandra, B.R.In this work, we report a facile two-step electrodeposition method to fabricate a CoMnS/NiCo2S4/NF (CMS/NCS/NF) composite on nickel foam (NF) for application of supercapacitor electrode. The electrochemical performance of this composite material has been extensively investigated, revealing superior performance compared to individual CMS/NF and NCS/NF materials. The CMS/NCS/NF composite exhibits an exceptionally high specific capacity of 707 C/g at a current density of 1 A/g in a three-electrode system. Remarkably, the material retains 92 % of its specific capacitance after 5000 cycles, indicating excellent cyclic stability and durability. To further explore its practical applications, we constructed a two-electrode symmetric supercapacitor using the CMS/NCS/NF electrode. This symmetric cell demonstrates an outstanding energy density of 97.5 Wh/kg and a peak power density of 12 kW/kg, underscoring its potential for high-performance energy storage applications. These comprehensive studies indicate that the synthesized CMS/NCS/NF is a highly promising candidate for supercapacitor electrodes, offering both high capacity and long-term stability. This work paves the way for the development of efficient and durable energy storage devices. © 2024 Elsevier Ltd