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Item Biomass waste-derived porous graphitic carbon for high-performance supercapacitors(Elsevier Ltd, 2024) Hegde, S.S.; Badekai Ramachandra, B.R.Porous carbons possess considerable appeal and are in high demand as materials that can be produced from biomass waste. This study presents the transformation of Tectona grandis (Teak) sawdust into porous carbon materials, referred to as Tectona grandis sawdust-derived porous carbon (TPC), through a cost-effective FeCl3-assisted carbonization process, followed by a KOH activation. TPC samples were synthesized by carbonization at different temperatures (650–850 °C) and characterized comprehensively. Structural analysis via X-Ray diffraction (XRD), Raman, and Fourier Transform Infrared Spectroscopy (FTIR) revealed a progressive enhancement in graphitic structure and reduction of functional groups with increasing activation temperature. Field emission scanning electron microscopy (FESEM) displayed the development of intricate hollow tube-like porous networks in TPC-850, with the highest specific surface area (1767.66 m2/g) and pore volume (1.43 cm3/g). Electrochemical investigations showcased the superior performance of TPC-850 as a supercapacitor electrode due to its high graphitic nature, large surface area, and well-structured porosity. The galvanostatic charge-discharge (GCD) measurements exhibited a high specific capacitance of 572 F/g at 0.5 A/g in a 6 M KOH electrolyte. The high-frequency semicircle and low-frequency steeper region in electrochemical impedance spectroscopy (EIS) further indicated reduced resistance and enhanced ion diffusion in TPC-850. Significantly, TPC-850 demonstrated remarkable electrochemical cyclic stability, retaining 95.83 % of its initial capacity even after undergoing 4500 cycles at a scan rate of 500 mV/s. The findings underscore the viability of TPC-850 as a high-performance supercapacitor electrode material, providing insights into harnessing renewable resources for advanced energy solutions. This work highlights the potential of utilizing waste biomass for energy storage applications and demonstrates the feasibility of converting it into efficient porous carbon materials with substantial graphitization and porosity. © 2023 Elsevier LtdItem Sustainable energy storage: Mangifera indica leaf waste-derived activated carbon for long-life, high-performance supercapacitors(Royal Society of Chemistry, 2024) Hegde, S.S.; Badekai Ramachandra, B.R.Biomass waste-derived activated carbon has a wide range of applications, including air and water purification, gas separation, energy storage, and catalysis. This material has become increasingly popular in recent years as a result of the growing demand for sustainable and eco-friendly materials. In this study, Mangifera indica leaf waste-derived activated carbon has been investigated as an electrode material for high-performance supercapacitors. The dried Mangifera indica leaves were first carbonized using FeCl3 and then activated using KOH to increase their surface area and pore structure at different temperatures. The activated carbon prepared at 725 °C has shown a high specific capacitance of 521.65 F g−1 at a current density of 0.5 A g−1 and also achieved an energy density of 17.04 W h kg−1 at a power density of 242.50 W kg−1 in the 6 M KOH electrolyte. Significantly, it has demonstrated remarkable electrochemical cycling stability, retaining 96.60% of its initial capacity even after undergoing 10 001 cycles at a scan rate of 500 mV s−1. The superior electrochemical performance of the activated carbon can be attributed to its high surface area of 1232.63 m2 g−1, well-distributed pore size, and excellent degree of graphitization, which all facilitate the rapid diffusion of ions and enhance the accessibility of the electrolyte to the electrode surface. Hence, this study provides a promising route for utilizing waste biomass as a low-cost, sustainable electrode material for energy storage devices. © 2024 The Royal Society of Chemistry.Item Significance of transition metal (Co, Ni and Zn) doping on the nano MnSe for high-performance supercapacitor electrode(Elsevier Ltd, 2024) Mascarenhas, F.J.; Rodney, J.D.; Kim, B.C.; Badekai Ramachandra, B.R.The demand for electrode materials in supercapacitors necessitates designs with exceptional performance, superior structure, and environmental sustainability, all while remaining affordable and abundantly available. This study introduces an economical hydrothermal synthesis method for producing MxMn1-xSe (M=Co / Ni / Zn) nanomaterials at varying concentrations (x = 0.0, 0.01, 0.02, and 0.03). Diverse characterization methods confirm the successful formation of nanomaterials. Among the materials studied, Co0.01Mn0.99Se nanoclusters exhibit superior performance as electrode materials for supercapacitors, delivering a specific capacitance of 421 F/g at 5 mV/s and 377 F/g at 1 A/g in a 5 M KOH solution. A two-electrode symmetric configuration was established utilizing Co0.01Mn0.99Se as the active material in a 5 M KOH electrolyte, yielding a notable specific capacitance of 73 F/g at 0.5 A/g. The maximum energy density and power density achieved are 20.44 Wh/kg and 2838 W/kg respectively. This configuration demonstrates the exceptional electrochemical performance and energy storage capabilities of Co0.01Mn0.99Se in a two-electrode system. Impressively, the symmetric cell maintains a significant 70% capacitance retention even after 5000 charge-discharge cycles. Considering these findings, the developed Co0.01Mn0.99Se emerges as a pivotal advancement, providing a robust framework for the development of cutting-edge energy conversion and storage technologies. © 2024 Elsevier B.V.Item Enhancing supercapacitor performance with zinc doped MnSe nanomaterial(Springer, 2024) Mascarenhas, F.J.; Badekai Ramachandra, B.R.The decreasing availability of fossil fuels and the increasing demand for energy highlight the pressing need for sustainable energy sources. Electrochemical technologies, notably supercapacitors, play a key role. They promise renewable energy storage, necessitating high-performing, safe, and affordable electrode materials. In this study, we present a novel hydrothermal synthesis method for producing MnSe and ZnxMn1-xSe materials across a range of concentrations (x = 0.01, 0.02, and 0.03). Characterization techniques including XRD, FESEM, HRTEM, BET and Raman analysis were employed. Among the synthesized compositions, Zn0.03Mn0.97Se emerged as the most promising material for supercapacitor applications. Evaluation through cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) revealed specific capacitance values of 135 F/g at 3 mV/s and 95 F/g at 0.5 A/g for Zn0.03Mn0.97Se. Furthermore, the material demonstrated impressive stability, retaining 97% of its capacitance after 1000 cycles. Additionally, to validate the potential of the synthesized electrode, we assembled a two-electrode symmetric cell using Zn0.03Mn0.97Se as both positive and negative electrode material in a 5 M KOH electrolyte. Extensive characterization techniques, including CV, GCD, and long-term cyclic stability tests, revealed compelling evidence of the material’s robust electrochemical behavior. These findings underscore the potential of Zn0.03Mn0.97Se for supercapacitors, contributing to the advancement of sustainable energy storage. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.Item Impact of electrolyte concentration on electrochemical performance of Cocos nucifera Waste-Derived High-Surface carbon for green energy storage(Elsevier Ltd, 2024) Hegde, S.S.; Badekai Ramachandra, B.R.The increasing popularity of utilizing biomass's natural structure represents a promising avenue for sustainable innovation, as it taps into the inherent characteristics of organic materials to address various environmental and industrial challenges. Researchers and industries continue to explore the full potential of biomass in creating more sustainable and efficient solutions. The transformation of biomass into carbon materials is an indirect means of utilizing CO2 as a carbon source, thus contributing to the sustainable development of energy storage technologies and also in pollution reduction. In the quest for sustainable energy solutions, this research unveils a cost-effective approach to supercapacitor development by harnessing the untapped potential of Cocos nucifera trunk sawdust-derived high-surface carbon (CHSC). Through a meticulous process involving ZnCl2 treatment and KOH activation at varying temperatures, CHSC-700 emerges as a standout electrode material with exceptional structural characteristics, boasting enhanced graphitization and a specific surface area of 1153.72 m2/g. Further, the study delved into the nuanced relationship between electrolyte concentration and supercapacitor performance, pinpointing 6 M KOH as the optimal condition. In 6 M KOH, the electrode exhibits a maximum specific capacitance of 559.27F/g at the current density of 0.5 A/g with outstanding cyclic stability, retaining 80.37 % capacitance after 20,000 cycles and an impressive energy density of 18.92 Wh/kg and power density of 246.75 W/kg. This systematic exploration provides valuable data for understanding the biomass-derived carbon electrode's behaviour under various electrolyte concentrations, offering crucial information for optimizing its performance in practical applications, such as energy storage devices. © 2024 Elsevier LtdItem 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 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.Item Cerium-Modulated Zinc Oxide for enhanced Photoelectrochemical Non-Enzymatic biosensing of Cholesterol: An experimental and First Principle Analysis(Elsevier B.V., 2024) Rao, L.; Rodney, J.D.; Joy, A.; Shivangi Nileshbhai, C.; James, A.; S, S.; Joyline Mascarenhas, F.; Udayashankar, N.K.; Anjukandi, P.; Chul Kim, B.; Badekai Ramachandra, B.R.Herein, we synthesized CexZn1-xO (x = 0.00, 0.01, 0.02, and 0.03) using the wet chemical method. The investigation explores photoelectrochemical (PEC) biosensors for enzyme-free detection of cholesterol, employing Ce0.03Zn0.97O (CZO3)/Nickel Foam (NF) as the active material. The investigation revealed notable enhancements in sensitivity for cholesterol detection, with a recorded activity of 2.812 mA.mM?1.cm?2, marking a twofold increase in comparison to dark mode (1.37 mA.mM?1.cm?2). The Limit of Detection (LOD) was determined to be 17 µM (light) and 28 µM (dark), while the Limit of Quantification (LOQ) was measured at 54 µM (light) and 98 µM (dark) in 0.1 M KOH solution. These findings demonstrate a linear detection range spanning from 80 µM to 2 mM. Ab-initio calculations based on Density Functional Theory (DFT) were carried out on 101 surfaces of both pristine ZnO and CZO3 to understand how the doping affected the pristine ZnO band gap. The findings indicate that CZO3 exhibits superior activity compared to pristine ZnO, underscoring its enhanced performance and potential for sensing application. The CZO3/NF photoelectrochemical (PEC) biosensor displayed notable cyclic stability, retaining 97 % of its performance over a 60-day period. This underscores its potential for reliable and enduring operation in biosensing applications. Additionally, CZO3/NF exhibited robust sensing capabilities when utilized with human serum samples, showcasing consistent performance in both dark and illuminated conditions. © 2024 Elsevier B.V.Item Sustained hydrogen production through alkaline water electrolysis using Bridgman–Stockbarger derived indium-impregnated copper chromium selenospinel(Elsevier Ltd, 2024) Jauhar, R.M.; Raji, R.; Deepapriya, S.; Raja, A.; Rao, L.; Joshi, S.; Era, P.; Badekai Ramachandra, B.R.; Udayashankar, N.K.; Vadivel, V.; Mangalaraja, R.V.; J, J.; Ghfar, A.A.; Senthilpandian, M.; Kim, B.C.; Rodney, J.D.The depletion of conventional fossil fuels necessitates the development of sustainable energy alternatives, with electrochemical water splitting for hydrogen (H2) production being a promising solution. However, large-scale hydrogen generation is hindered by the scarcity of cost-effective electrocatalysts to replace noble metals such as Pt and RuO2 in the Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER). In this study, we report the synthesis of CuCr2-xInxSe4 (x = 0, 0.2, 0.4) using a dual approach combining the Bridgman-Stockbarger method and ball milling. Among the synthesized materials, CuCr1.8In0.2Se4 demonstrates outstanding HER activity in 1.0 M KOH, achieving a potential of ?0.16 V vs. RHE at a current density of 10 mA cm?2. Moreover, the material shows remarkable durability during a three-electrode accelerated degradation test in an alkaline medium, maintaining its performance over 24 h at a constant current density of ?200 mA cm?2, with a stable potential of ?0.57 V vs. RHE. Additionally, CuCr1.8In0.2Se4 was tested in a two-electrode configuration alongside CoFe LDH, achieving a benchmark of 1.7 V for overall water splitting. It sustained a current density of 400 mA cm?2 for 24 h in an accelerated degradation test, exhibiting a minimal loss of 0.1 V after the testing period. These results highlight CuCr1.8In0.2Se4 as a promising non-noble metal catalyst for HER, demonstrating its potential to reduce reliance on noble materials for large-scale hydrogen production. © 2024 Hydrogen Energy Publications LLC