Prabhat Kumar College

About: Prabhat Kumar College is a based out in . It is known for research contribution in the topics: Schiff base & Scalar field. The organization has 39 authors who have published 109 publications receiving 574 citations.

Boosting the Supercapacitive Performance of ZnO by 3-Dimensional Conductive Wrapping with Graphene Sheet

Abstract: ZnO is considered a promising pseudocapacitive material for supercapacitor devices because of its high specific energy density, low cost, non-toxicity, eco-friendliness, and widespread availability. However, its poor electronic and ionic conductivity limits its power density and cycling stability as a supercapacitor device, restricting its use in energy storage systems. Herein we report a novel hybrid nanocomposite electrode material developed by three-dimensional conducting wrapping of ZnO nanoparticles with graphene sheet to significantly improve the supercapacitor efficiency. The wrapping of ZnO nanospheres by graphene sheets creates highly conductive pathways by bridging individual ZnO together, thereby improving the rate and cycling performance of supercapacitors. The fabricated supercapacitor device using this ZnO–RGO hybrid exhibited a high specific capacitance of 1012 F/g at a current density of 1 A/g. Furthermore, the ZnO–RGO hybrid is capable of achieving an outstanding power density of 3534.6 W/kg, an energy density of 50.6 Wh/kg and a Coulombic efficiency of 96.4%. These findings exhibit the potential of the ZnO–RGO hybrid nanocomposites as an electrode in high-performance supercapacitors.

A combined theoretical and experimental investigation of DNA interactive poly-hydroxyl enamine tautomer exhibiting “turn on” sensing for Zn2+ in pseudo-aqueous medium

Abstract: Crystallographically established (solid state structure at 150 K temperature) enamine ligand 2-((1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylamino)methyl)-4-bromo-6-methoxyphenol (H4L) was prepared, which showed interconvertible equilibrium (ΔE = 7.37 kcal) of its tautomers and also found to exhibit DNA binding activity at the minor groove of double-stranded (ds) DNA. Spectroscopic and calorimetric methods were employed to explore the interaction of H4L with DNA. Further, the competitive Hoechst 33258 displacement assay indicated the specific binding site of H4L to be at the minor grooves of DNA. Thermodynamic evaluation from isothermal titration calorimetry (ITC) experiments suggested the association of H4L with DNA to be an enthalpy driven process with an equilibrium binding affinity (K) of (2.50 ± 0.11) × 104 M−1. Molecular docking studies were found to be in good agreement with the experimental results of the DNA interaction of the probe in groove binding mode. The poor emission of H4L in the excited state was due to excited state induced proton transfer (ESIPT), but in the presence of Zn2+, the ESIPT was blocked an chelation-enhanced fluorescence (CHEF) was initiated to exhibit ‘turn on’ fluorescence upon the coordination of Zn2+. The H4L probe was found to detect Zn2+ selectively among various metal ions and the LOD was calculated to be ∼1.13 μM. The coordination of the Zn(II) bound complex and the relative stability of the tautomers of H4L were investigated in detail via spectroscopic and computational studies.

Resonance fluorescence microscopy via three-dimensional atom localization

Abstract: A scheme is proposed to realize three-dimensional (3D) atom localization in a driven two-level atomic system via resonance fluorescence. The field arrangement for the atom localization involves the application of three mutually orthogonal standing-wave fields and an additional traveling-wave coupling field. We have shown the efficacy of such field arrangement in tuning the spatially modulated resonance in all directions. Under different parametric conditions, the 3D localization patterns originate with various shapes such as sphere, sheets, disk, bowling pin, snake flute, flower vase. High-precision localization is achieved when the radiation field detuning equals twice the combined Rabi frequencies of the standing-wave fields. Application of a traveling-wave field of suitable amplitude at optimum radiation field detuning under symmetric standing-wave configuration leads to 100% detection probability even in sub-wavelength domain. Asymmetric field configuration is also taken into consideration to exhibit atom localization with appreciable precision compared to that of the symmetric case. The momentum distribution of the localized atoms is found to follow the Heisenberg uncertainty principle under the validity of Raman–Nath approximation. The proposed field configuration is suitable for application in the study of atom localization in an optical lattice arrangement.

Synthesis and Characterization of Super Paramagnetic Iron Oxide Nanoparticles

Abstract: Iron oxide (γ-Fe2O3) nanoparticles have been prepared by a simplified coprecipitation method. X-ray diffraction peaks of the prepared nanoparticles match well with the characteristic peaks of crystalline g-Fe2O3 as per JCPDS data (JCPDS Card No. 39-1346) and absorption peak at 369 nm along with band gap 2.10 eV suggesting the formation of (γ-Fe2O3) nanoparticles. The γ-Fe2O3 nanoparticles are spherical in nature with a diameter around ~10 nm. The crystalline g-Fe2O3 nanoparticles exhibit excellent super-paramagnetic behavior not only at room temperature (300K) but also at a temperature as low as 100K.