Mallikarjuna Koduru - Academia.edu (original) (raw)

Papers by Mallikarjuna Koduru

Crystals, 2021

Zinc cobaltite (ZnCo2O4) is an emerging electrode material for supercapacitors due to its rich re... more Zinc cobaltite (ZnCo2O4) is an emerging electrode material for supercapacitors due to its rich redox reactions involving multiple oxidation states and different ions. In the present work, potato chip-like 0D interconnected ZnCo2O4 nanoparticles (PIZCON) were prepared using a solvothermal approach. The prepared material was characterized using various analytical methods, including X-ray powder diffraction and scanning electron microscopy. The possible formation mechanism of PIZCON was proposed. The PIZCON electrode material was systematically characterized for supercapacitor application. The areal capacitance of PIZCON was 14.52 mF cm−2 at 10 µA cm−2 of current density, and retention of initial capacitance was 95% at 250 µA cm−2 following 3000 continuous charge/discharge cycles. The attained measures of electrochemical performance indicate that PIZCON is an excellent supercapacitor electrode material.

international journal of nano dimension, 2011

In this paper we report an eco-friendly route for the synthesis of sliver nanoparticles using Aga... more In this paper we report an eco-friendly route for the synthesis of sliver nanoparticles using Agaricus bisporus (white button mushroom) extract. The synthesized silver nanoparticles were confirmed and characterized by UV-Visible spectrum of the aqueous solution containing silver ions showed a peak at 420 nm corresponding to the surface plasmon absorbance of silver nanoparticles. Transmission Electron Microscopy (TEM) micrographs showed the size of silver nanoparticles and were measured in the range of 8-50nm, Fourier Transform Infrared Spectroscopy (FTIR) spectrum detection of analysis showed peaks between 500-4000 cm-1 confirmed the presence of proteins, carbonyl groups, esters and carboxylic acids for the synthesis and stabilization of silver nanoparticles .X-ray diffraction (XRD) spectrum of the silver nanoparticles exhibited 2θ values corresponding to the silver nanocrystal. Further, the antibacterial activity of synthesized silver nanoparticles showed effective inhibitory activ...

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy

An invitro study was conducted to investigate the antifungal properties of silver nanoparticles s... more An invitro study was conducted to investigate the antifungal properties of silver nanoparticles synthesized from edible mushrooms (Agaricus bisporus). The synthesized and characterized silver nanoparticles exhibited an excellent antifungal property on pathogenic fungal strain Aspergillums niger, causative agent of Aspergillosis disease

Applied Nanoscience, 2015

Facile approach to synthesize the metal oxide nanoparticles is getting an increased attention in ... more Facile approach to synthesize the metal oxide nanoparticles is getting an increased attention in various biomedical applications such as, to treat antibiotic resistant diseases. Magnesium oxide nanoparticles (MgOÁNPs) were synthesized by using Clitoria ternatea as the stabilizer in a green synthesis approach. The preliminary screening of MgOÁNPs in the presence of C. ternatea extract was observed by UV-visible spectrophotometer. X-ray diffraction (XRD) pattern have proved the crystalline nature of the MgOÁNPs; Photoluminescence (PL) measurement studies are used to identify the quality and defects in the crystal structure. FE-SEM with EDS has showed the size of 50-400 nm with specific binding energies. FT-IR has revealed the functional groups present in the plant extract and the peak at 521 cm-1 indicated the characteristic absorption bands of MgOÁNPs. The DPPH activity and reducing power assay of biologically synthesized MgOÁNPs could reach 65 % at a concentration of 150 lg/ml, respectively. From the results it was concluded that the biologically synthesized MgOÁNPs exhibit good antioxidant activity.

Arabian Journal of Chemistry, 2013

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011

Single crystals of ␥-glycine, an organic nonlinear optical material have been synthesized in the ... more Single crystals of ␥-glycine, an organic nonlinear optical material have been synthesized in the presence of potassium fluoride (KF) by slow evaporation technique at ambient temperature. The size of the grown crystal is up to the dimension of 12 mm × 10 mm × 8 mm. The ␥-phase was confirmed by single crystal X-ray diffraction, powder XRD and the FTIR analysis. Optical absorption spectrum reveals that the grown crystal has good optical transparency in the entire visible region with an energy band gap of 5.09 eV, which is an essential requirement for a nonlinear optical crystal. Thermal stability of the grown ␥-glycine crystal was determined using the thermo gravimetric and differential thermal analyses. The NLO activity of ␥glycine was confirmed by the Kurtz powder technique using Nd:YAG laser and the grown crystal exhibits high relative conversion efficiency when compared to potassium dihydrogen phosphate (KDP).

Journal of Alloys and Compounds, 2014

Journal of Nanoscience and Nanotechnology, 2015

Exploitation of green chemical procedures for the synthesis of metal nanoparticles by biological ... more Exploitation of green chemical procedures for the synthesis of metal nanoparticles by biological process has received great attention in the field of nanotechnology. To demonstrate a biogenic method that involves the reduction of aqueous gold ions by the extract of Piper longum leaves leading to the formation of different morphological gold nanoparticles (AuNPs). The formation of gold nanostructures has been characterized by UV-Vis absorption spectroscopy. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns indicates the AuNPs are highly crystalline nature with the face-centered cubic (111), (200), (220) and (311) facets, respectively. The AuNPs have different sizes and morphologies that are identified by TEM studies. The involvement of water soluble bio-molecules such as carboxylic acids, flavonoids, proteins and terpenoids were identified by Fourier transform infrared (FT-IR) and Raman spectrum. The responsible mechanism of improving acidic nature and the process of encapsulation of gold nanoparticles by Piper longum extract was discussed. Additionally, we have demonstrated the modified carbon paste electrode using gold nanoparticles by means of cyclic voltammetry in a solution of 1 M KCl and 1 mM [Fe(CN) 6 ] 3−/4−. The analysis of cyclic voltammetry shows electronic transmission rate between modified Au-CPE and Bare-CPE electrode increased.

Springer Proceedings in Physics, 2013

Proliferation of green chemical nanoscience research has opened up novel fundamental and frontier... more Proliferation of green chemical nanoscience research has opened up novel fundamental and frontiers in material science and medical research. Integration of green chemistry principles to nano is one of the key issues of nanoscience and technology research. Interdisciplinary nanoscience research involving physicists, chemists, biologists and material engineers are concerned about the need for developing eco-friendly methods to synthesize of nano materials [1, 2]. Among the noble metal nanoparticles, gold nanoparticles has fascinating chemical and physical properties and has important value in the fundamental and application research fields [3, 4]. Traditionally, nanoparticles have been prepared by a number of physical and chemical methods like laser ablation, pyrolysis, lithography, chemical vapor deposition, sol-gel technique and electro deposition techniques, which are slow,

Arabian Journal of Chemistry, 2014

The Pepper leaves extract acts as a reducing and capping agent in the formation of silver nanopar... more The Pepper leaves extract acts as a reducing and capping agent in the formation of silver nanoparticles. A UV-Vis spectrum of the aqueous medium containing silver nanoparticles demonstrated a peak at 458 nm corresponding to the plasmon absorbance of rapidly synthesized silver nanoparticles that was characterized by UV-Vis spectrophotometer. The morphology and size of the benign silver nanoparticles were carried out by the transmission electron microscope (TEM) and field emission scanning electron microscope (FE-SEM). The sizes of the synthesized silver nanoparticles were found to be in the range of 5-60 nm. The structural characteristics of biomolecules hosted silver nanoparticles were studied by X-ray diffraction. The chemical composition of elements present in the solution was determined by energy dispersive spectrum. The FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. This study reports that synthesis is useful to avoid toxic chemicals with adverse effects in medical applications rather than physical and chemical methods.

Journal of Physics and Chemistry of Solids, 2014

A red-emitting phosphor NaSrB 5 O 9 :Eu 3 þ was synthesized by employing a solid-state reaction (... more A red-emitting phosphor NaSrB 5 O 9 :Eu 3 þ was synthesized by employing a solid-state reaction (SSR) method. The structures of the phosphors were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman studies. The band at $ 282 nm in the excitation spectra indicated the charge transfer band (CTB) of B-O in the host, whereas the CTB of Eu-O was observed at $ 275 nm for the NaSrB 5 O 9 :Eu 3 þ (Eu 3 þ ¼1 at.%) phosphor, which was supported by diffuse reflectance spectroscopy (DRS) measurements. The photoluminescence (PL) measurements exhibited a strong red emission band centered at about 616 nm (5 D 0-7 F 2) under an excitation wavelength of 394 nm (7 F 0-5 L 6). Upon host excitation at 282 nm, the pristine NaSrB 5 O 9 exhibited a broad UV emission centered at $ 362 nm. The energy transfer from host to Eu 3 þ ions was confirmed from luminescence spectra, excited with a 355 nm Nd:YAG laser. In addition, the asymmetric ratios indicate a higher local symmetry around the Eu 3 þ ion in the host. The calculated CIE (Commission International de l′Eclairage) coordinates displayed excellent color purity efficiencies (around 99.7%) compared to other luminescent materials.

Journal of Molecular Structure, 2012

ABSTRACT This study reports on the concentration dependent fluorescence properties of Tb 3+ -dope... more ABSTRACT This study reports on the concentration dependent fluorescence properties of Tb 3+ -doped lead containing calcium zinc sodium fluoroborate (LCZSFB) glasses and are analyzed by DSC, FT-IR, FT-Raman, optical absorption, emission and decay curve spectra. Co-existence of trigonal BO 3 and tetrahedral BO 4 units was evidenced by FT-IR and Raman spectroscopy. Judd–Ofelt theory was applied to the experimental oscillator strengths to evaluate the J–O intensity parameters. The fluorescence spectra of Tb 3+ -doped glasses have revealed prominent blue and green emissions originating from 5 D 3 and 5 D 4 excited levels to 7 F J ground state multiplet, respectively. The luminescent intensity of the transitions originating from 5 D 4 state increases with increase of Tb 3+ concentration and no quenching effect is noticed up to 2 mol% of Tb 3+ ions. Chromaticity color coordinates have been calculated and the dominant emission in the green region is discussed. The nature of decay curves of 5 D 4 level for different Tb 3+ ion concentration in all LCZSFB glasses has been analyzed. Using the J–O intensity parameters as well as from the emission and decay curve measurements, various radiative and fluorescence properties have been calculated for the 5 D 4 fluorescent level. Based on these results, the utility of Tb 3+ ions doped LCZSFB glasses as laser active materials for high intensity emissions in the green region is discussed. Ó 2012 Elsevier B.V. All rights reserved.

Journal of Luminescence, 2011

Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar composition of 20PbO... more Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar composition of 20PbOþ 5CaO þ5ZnO þ10NaFþ (60 À x) B 2 O 3 þ x Sm 2 O 3 , (x ¼ 0.1, 0.25, 0.5, 1.0 and 2.0 mol%) were prepared and investigated by the XRD, FTIR, optical absorption, photoluminescence and decay curve analysis. Judd-Ofelt theory was applied to the experimental oscillator strengths to evaluate the phenomenological J-O intensity parameters X l (l¼ 2, 4 and 6). Using the J-O intensity parameters as well as from the emission and decay measurements, various radiative parameters such as transition probabilities (A R), radiative lifetimes (t R), measured lifetimes (t m), calculated branching ratios (b R), measured branching ratios (b m), effective bandwidth (Dl eff) and stimulated emission cross sections s(l p) have been calculated for the excited 4 G 5/2 luminescent level. The nature of decay curves of 4 G 5/2 level for different Sm 3 þ ion concentrations in all LCZSFB glasses has been analyzed and the lifetimes are noticed to decrease with increase of concentration. The concentration quenching has been attributed to the energy transfer through the cross-relaxation between Sm 3 þ ions. Based on these results, the utility of Sm 3 þ ions doped lead containing fluoroborate glasses as laser active materials in the visible region is discussed.

Analytical Methods, 2013

ABSTRACT A novel chemically modified electrode was constructed based on the electrodeposition of ... more ABSTRACT A novel chemically modified electrode was constructed based on the electrodeposition of palladium nanoparticles (PdNps) on to a poly(solochrome cyanine) (polySCCy) film coated carbon paste electrode (CPE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) were used to characterize the properties of the modified electrode. The polySCCy/PdNPs/CPE was used for the impressionable, individualized determination and simultaneous resolution of dopamine (DA), ascorbic acid (AA) and uric acid (UA) in 0.1 M acetate buffer solution (ABS) of pH 5.0 by employing CV and DPV. The polySCCy/PdNPs/CPE exhibited strong electrocatalytic activity towards the oxidation of a mixture solution of DA, AA and UA with obvious redox potentials. The overlapping voltammetric response of biomolecules were separated into three well resolved oxidation peaks for DA, AA and UA with lower oxidation potentials and significant increase in the anodic peak currents in the presence of polySCCy/PdNPs/CPE by using CV and DPV. The results showed good sensitivity, selectivity and high reproducibility of the electrosynthesized polymer nanoparticles inclusion electrode. The limit of detection, limit of quantification and correlation coefficient of DA at polySCCy/PdNPs/CPE were 1.87 μM, 6.24 μM and 0.99375, respectively. The developed chemical sensor is ideal for the analysis of DA in pharmaceutical formulations providing satisfactory results. The interfacial electron transfer rate of DA was studied by EIS.

Journal of Luminescence

a b s t r a c t Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar comp... more a b s t r a c t Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar composition of 20PbOþ 5CaO þ5ZnO þ10NaFþ (60 À x) B 2 O 3 þ x Sm 2 O 3 , (x ¼ 0.1, 0.25, 0.5, 1.0 and 2.0 mol%) were prepared and investigated by the XRD, FTIR, optical absorption, photoluminescence and decay curve analysis. Judd–Ofelt theory was applied to the experimental oscillator strengths to evaluate the phenomenological J–O intensity parameters X l (l¼ 2, 4 and 6). Using the J–O intensity parameters as well as from the emission and decay measurements, various radiative parameters such as transition probabilities (A R), radiative lifetimes (t R), measured lifetimes (t m), calculated branching ratios (b R), measured branching ratios (b m), effective bandwidth (Dl eff) and stimulated emission cross sections s(l p) have been calculated for the excited 4 G 5/2 luminescent level. The nature of decay curves of 4 G 5/2

Research Journal of Nanoscience and Nanotechnology, 2012

Abstract: Nanotechnology can be defined as a research for the design, synthesis and manipulation ... more Abstract: Nanotechnology can be defined as a research for the design, synthesis and manipulation of structure of particles with dimension smaller than 100 nm. Nanotechnology emerges from the physical, chemical, biological and engineering sciences where novel ...

ptical absorption and photoluminescence studies have been carried out at room temperature in 25 R... more ptical absorption and photoluminescence studies have been carried out at room temperature in 25 R2O–25 GeO2–49.5 B2O3–0.5 Nd2O3 glass systems, (Composition in mol%, R = Li, Na, K and Rb). Judd Ofelt Intensity parameters and other parameters like Racah (E1, E2 and E3), Slater–Condon–Shortley (F2, F4 and F6) Spin-Orbit Coupling (ξ4f) and Configuration Interaction (α,β and γ) for Nd3+ ion in the glass system are calculated. The variation of the Ω2 parameters are interpreted in terms of the covalency of the RE ion in the glass matrix. Further the hypersensitive transition 4I9/2 → 4 G5/2, 2 G7/2 is analyzed with respect to the intensity ratio IL/IS and is found to be dependent on the type of alkali in the glass matrix. The Photoluminescence studies do not show any appreciable shift in the peak emission wavelength of the 4 F3/2 to 4I11/2 transition with the change in alkali type. Research Highlights