Faculty Publications
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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 Biosynthesis of cobalt oxide nanoparticles using endophytic fungus Aspergillus nidulans(Academic Press, 2018) Vijayanandan, A.S.; Mohan Balakrishnan, R.M.Metallic oxide nanoparticles have profound applications in electrochemical devices, supercapacitors, biosensors and batteries. Though four fungi were isolated from Nothapodytes foetida, Aspergillus nidulans was found to be suitable for synthesis of cobalt oxide nanoparticles, as it has proficient tolerance towards metal under study. The broth containing precursor solution and organism Aspergillus nidulans had changed from pink to orange indicating the formation of nanoparticles. Characterization by x-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and energy dispersive x-ray analysis (EDX) confirmed the formation of spinel cobalt oxide nanoparticles at an average size of 20.29 nm in spherical shape with sulfur-bearing proteins acting as a capping agent for the synthesized nanoparticles. The nanoparticles could be applied in energy storage, as a specific capacitance of 389 F/g showed competence. The study was a greener attempt to synthesize cobalt oxide nanoparticles using endophytic fungus. © 2018 Elsevier LtdItem Decolorization of Reactive Blue 220 aqueous solution using fungal synthesized Co3O4 nanoparticles(IWA Publishing 12 Caxton Street London SW1H 0QS, 2019) Valappil, R.S.K.; Vijayanandan, A.S.; Mohan Balakrishnan, R.M.In this work, the photocatalytic activity of the biosynthesized cobalt oxide (Co3O4) nanoparticle (NP) is investigated using a textile dye Reactive Blue 220 (RB220) and decolorization % was monitored using UV–Vis spectrophotometer. The photocatalytic activity has been observed maximum at alkaline pH of 9, NP dosage of 250 mg/L, and reaction time of 270 min. In the presence of UV light irradiation, a maximum dye concentration of 10 mg/L was treated effectively using 150 mg/L NP, and 67% decolorization was achieved. Reaction kinetics has been analyzed, and the reaction followed the pseudo kinetics model with an activation energy of -484 kJ mol-1. © IWA Publishing 2019Item Polypyrrole functionalized Cobalt oxide Graphene (COPYGO) nanocomposite for the efficient removal of dyes and heavy metal pollutants from aqueous effluents(Elsevier B.V., 2021) Anuma, S.; Mishra, P.; Badekai Ramachandra, B.R.A cobalt oxide graphene nanocomposite functionalized with polypyrrole (COPYGO) having a heterogenous porous structure was synthesized using hydrothermal method. Microscopic imaging of the COPYGO surface revealed its highly porous and ordered features. The adsorption performance of the COPYGO composite was systemically investigated for Methylene Blue (MB), Congo red (CR) dyes and toxic lead (Pb(II)) and Cadmium (Cd(II)) metals. These were selected as they are the common pollutants in industrial wastewater. The COPYGO was found to be thermally stable up to 195 oC with a specific surface area of 133 m2 g?1. Experimental data indicates that the COPYGO follows Langmuir and Temkin adsorption isotherm. The COPYGO was efficient in removing MB (92.8%), CR (92.2%), Pb(II) (93.08%) and Cd(II) (95.28%) pollutants at pH 7.2, 5.0, 5.5 and 6.1 respectively from the simulated effluents. The maximum adsorption capacity (Qmax) observed for MB 663.018 mg g-1, CR 659.056 mg g-1, Pb(II) 780.363 mg g?1 and Cd(II) 794.188 mg g?1 pollutants. The thermodynamic analysis of the COPYGO indicates that the adsorption is endothermic and spontaneous in nature. COPYGO showed very high efficient removal rate for the pollutants in simulated effluents which guaranteed its benefits and efficacy in industrial wastewater treatment. © 2021 Elsevier B.V.Item Identification, purification and functional characterization of a thermostable marine chitinase for potential fungal control via chitin degradation mechanism(Elsevier Ltd, 2025) Atheena, P.V.; Raval, K.; Raval, R.The growing prevalence of treatment-resistant Candida species highlights an urgent need for innovative antifungal therapies. The current range of antifungals, limited to polyenes, azoles, and echinocandins, are becoming insufficient due to the rise of resistance, including cross-resistance among fungal strains. Marine environment is an underexplored reservoir of unique enzymes which can be extremophilic. This study presents the cloning and expression of a chitinase gene from the bacterium Bacillus thuringiensis (BtChi), expressed in an E. coli system, yielding a protein with a molecular weight of approximately 71 kDa. Disc diffusion and MIC experiments indicated that 5 ?g/mL chitinase efficiently suppressed the growth of Candida albicans. Initial characterization identified the optimal activity at 40 °C and pH 7.0. The enzyme retained over 75 % activity across a pH range of 4–8 and a temperature range of 30–70 °C after 120 min. Activity was further enhanced by 24 % with 100 mM Na+. Kinetic parameters with colloidal chitin revealed Km and Vmax values to be 0.05 mg/mL and 1.37 U/mL respectively. This study holds the potential of developing a potent natural anti-fungal against the present day chemical counterparts. © 2025 The Authors