Faculty Publications
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Item Single-step oxidative homocoupling of aryl Grignard reagents via Co(II), Ni(II) and Cu(II) Complexes under air(John Wiley and Sons Ltd Southern Gate Chichester, West Sussex PO19 8SQ, 2014) Bhat, A.P.I.; Badekai Ramachandra, B.R.A simple catalytic system of direct synthesis for the symmetrical biaryls using catalytic amounts of Co(II), Ni(II) and Cu(II) complexes has been developed. The reaction system involves in situ synthesis of Grignard reagents. The complexes, containing bidentate Schiff base and dmit (2-thioxo-1,3-dithiole- 4,5-dithiolate) ligands, were compatible with diverse functionalities and afford a high yield of biaryls in a single step, proving to be promising catalysts in homocoupling reactions. Atmospheric oxygen is used as an oxidant which renders a green, simple and economical catalytic route. Copyright © 2014 John Wiley & Sons, Ltd.Item Nickel hydroxide/cobalt-ferrite magnetic nanocatalyst for alcohol oxidation(American Chemical Society service@acs.org, 2014) Bhat, P.B.; Inam, F.; Badekai Ramachandra, B.R.A magnetically separable, active nickel hydroxide (Brønsted base) coated nanocobalt ferrite catalyst has been developed for oxidation of alcohols. High surface area was achieved by tuning the particle size with surfactant. The surface area of 120.94 m2 g-1 has been achieved for the coated nanocobalt ferrite. Improved catalytic activity and selectivity were obtained by synergistic effect of transition metal hydroxide (basic hydroxide) on nanocobalt ferrite. The nanocatalyst oxidizes primary and secondary alcohols efficiently (87%) to corresponding carbonyls in good yields. © 2014 American Chemical Society.Item Plant root nodule like nickel-oxide-multi-walled carbon nanotube composites for non-enzymatic glucose sensors(Royal Society of Chemistry, 2015) Prasad, R.; Gorjizadeh, N.; Rajarao, R.; Sahajwalla, V.; Badekai Ramachandra, B.R.Herein, in this work we synthesized plant root nodule like NiO-MWCNT nanocomposites by a simple, rapid and solvent-free method using nickel formate as a precursor. Using a first-principle simulation study the interactions and charge transfer behaviour of the NiO and MWCNT composite is investigated. The as-prepared NiO-MWCNT composite is employed to fabricate a modified non-enzymatic carbon paste electrode (CPE) for glucose sensing. From the electrochemical investigation, the fabricated sensor shows an excellent sensitivity of 6527 ?A mM-1 cm-2 with a detection limit of 19 ?M and a linear response over a range from 0.001 mM to 14 mM of glucose concentrations, at an applied potential of 0.5 V. Importantly the sensor also exhibits greater stability, selectivity and reproducibility. A first principle simulation study shows the differences in charge density and charge transfer behaviour from nanotubes to NiO nanoparticles, which in turn enhances the electro catalytic property of the NiO-MWCNT composite. Hence, these results indicate that the NiO-MWCNT composite is a potential material for non-enzymatic electrochemical glucose sensors. This journal is © The Royal Society of Chemistry.Item Nickel-oxide multiwall carbon-nanotube/reduced graphene oxide a ternary composite for enzyme-free glucose sensing(Royal Society of Chemistry, 2016) Prasad, R.; Ganesh, V.; Badekai Ramachandra, B.R.We report a solvent-free method of preparation for a NiO-carbon nanotube/graphene ternary composite using nickel formate as a green precursor via a thermal decomposition method. In this ternary composite, NiO with an average particle size of 7 nm is regularly decorated on the surfaces of conductive carbon matrix networks such as MWCNTs and reduced graphene oxide (rGO). Here rGO serves as an ideal support for the uniform distribution of NiO nanoparticles and also functions as an efficient transducer material, whereas, MWCNTs act as a spacer between rGO, which enhances the electrical conductivity and accessibility of the active reaction sites for direct glucose oxidation. The electrochemical performances were evaluated by cyclic voltammetry and amperometric techniques. Under the optimal conditions, the 20 wt% NiO-MWCNT/rGO/GCE exhibits a sensitivity of 4223.3 ?A cm-2 mM-1 and a detection limit of 0.92 ?M over a linear glucose concentration range up to 19 mM. Furthermore, the constructed sensor is effectively employed to detect glucose in real human blood serum samples with adequate results. The modified 20 wt% NiO-MWCNT/rGO/GCE also shows a high sensitivity, greater selectivity, excellent reproducibility and long-term stability. © 2016 The Royal Society of Chemistry.Item RGO supported Co-Ni bimetallic magnetically separable nanocatalysts for the reduction of 4-Nitrophenol(Elsevier Ltd, 2016) Prasad, R.; Lolakshi, M.K.; Badekai Ramachandra, B.R.The Cobalt-Nickel-reduced graphene oxide ternary composite was prepared using eco-friendly, solvent-free and low temperature CVD method where in metal formates were used as metal precursor. The structure, composition and morphology of synthesized samples were characterized by several related techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The catalytic efficiency towards reduction of an organic pollutant such as 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was explored and the reaction parameters like temperature, weight ratio of the composite was optimised and rate constant of the reactions were measured. The results show 8% Co-Ni-rGO are having high catalytic efficiency and can complete the reduction reaction within 250 s at 45 °C. Furthermore, catalyst being magnetically separable shows high stability after ten successive reactions. Hence, the Co-Ni-rGO composite can be a potential promising material to catalyse the reduction of 4-NP. © 2016 Elsevier B.V. All rights reserved.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 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 Electrochemical insights into manganese-cobalt doped ?-Fe2O3 nanomaterial for cholesterol detection: a comparative approach(Royal Society of Chemistry, 2025) Sushmitha, S.; Ray, S.; Rao, L.; Nayak, M.P.; Carva, K.; Badekai Ramachandra, B.R.Herein, a self-assembled hierarchical structure of hematite (?-Fe2O3) was synthesized via a one-pot hydrothermal method. Subsequently, the nanomaterial was doped to obtain MxFe2?xO3 (M = Mn-Co; x = 0.01, 0.05, and 0.1) at precise concentrations. An electrode was fabricated by coating the resulting nanocomposite onto a nickel foam (NF) substrate. Electrochemical characterization demonstrated the excellent performance of cobalt-doped ?-Fe2O3, among which Co0.05Fe0.95O3 (CF5) exhibited a superior performance, showing a two-fold increase in sensitivity of 1364.2 ?A mM?1 cm?2 (±0.03, n = 3) in 0.5 M KOH, a limit of detection (LOD) of ?0.17 mM, and a limit of quantification (LOQ) of ?0.58 mM. The Density Functional Theory (DFT) was performed to understand the doping prompting in the reduced bandgap. The fabricated electrode displayed a rapid response time of 2 s and demonstrated 95% stability, excellent reproducibility, and selectivity, as confirmed by tests with several interfering species. A comprehensive evaluation of the electrode's performance using human blood serum highlighted its robustness and reliability for cholesterol detection in clinical settings, making it a promising tool for clinical and pharmaceutical applications. © 2025 The Royal Society of Chemistry.