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The current study aimed to access photocatalytic degradation of methylene blue (MB) dye using undoped CoFe2O4, 2%, 4%, and 6% Ni-doped CoFe2O4 nanoparticles synthesized via chemical co-precipitation method. X-ray diffraction (XRD) was performed for structural analysis which confirmed the spinel cubic structure of the prepared nanoparticles. Scanning electron microscopy (SEM) was performed for surface and morphological study revealing the agglomeration of nanoparticles due to magnetic behavior of CoFe2O4 nanoparticles. UV–visible absorption spectroscopy was performed, and bandgap was calculated using tauc plot, which revealed that bandgap increases with increasing Ni doping concentration in CoFe2O4 nanoparticles. Vibrating-sample magnetometry (VSM) was performed to study the magnetic behavior of synthesized nanoparticles, and it was observed that the saturation magnetization value is higher for 2% Ni-doped CoFe2O4 nanoparticles. Photocatalytic activities for the prepared samples were analyzed for MB as an organic pollutant. 2% Ni-doped sample possessed greater efficiency of 67% in degrading the organic pollutant (MB), whereas pure cobalt ferrite possessed 51.6%, respectively. This superior Photocatalytic performance of 2% Ni-doped cobalt ferrite nanoparticles may be associated with introduction of localized defect states that may lead to trapping of electrons to prevent their recombination and enhanced visible light absorption. These findings imply the potential of Ni-doped CoFe2O4 photocatalysts for the degradation of organic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

In this work, composite nanostructures (CNs) of SnO2–ZnO–g–C3N4 have been prepared by a soft chemical method and investigated for their potential application in photocatalytic remediation of organics in water and antibacterial agents. Structural study revealed the presence of three phases related to hexagonal wurtzite phase of ZnO, tetragonal phase of SnO2 and monoclinic phase of g–C3N4 having nanocrystalline nature which confirms the formation of CNs. Formation of nanoscale morphology along with elemental composition of the CNs have been validated through scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) spectroscopy. The presence of only A1g mode of SnO2 in Raman spectrum of ternary CNs suggested that SnO2 nanoparticles have been coated on the surfaces of ZnO and g–C3N4 which is also evident from SEM results. SnO2–ZnO–g–C3N4 CNs have shown much higher photocatalytic degradation efficiency and produced 7 mm greater zone of inhibition (ZOI) against Gram-positive S. Aureus bacteria as compared to pure ZnO which is quite significant result when compared to previously reported results for SnO2–ZnO CNs. These synthesized CNs may have potential uses in healthcare technology and treatment of organics in water. [ABSTRACT FROM AUTHOR]

The linear and nonlinear low-frequency collisional quantum Buneman instability in electronpositron- ion plasmas have been studied. Buneman instability in low frequency three species quantum plasma has been investigated using the approach of the quantum hydrodynamic model. The one-dimensional low-frequency collisional model is revisited by introducing the Bohm potential term in the momentum equation along with the role of the positron. Low-frequency Buneman instability which arises by one stream of particles drifting over another is investigated in the presence of the positron. Different plasma configurations based on the relative velocities of streaming particles are analyzed and it is observed that positron content enhances the instability in classical limits. Further, we found that in pure quantum limits the instability growth rate is decreased by increasing the positron concentration. The present work is very useful for the nonlinear problems in Quantum Coulomb systems. [ABSTRACT FROM AUTHOR]