Ultrathin hydrothermal carbonation carbon (HTCC)-coated cobalt ferrite (CoFe2O4) composites with HTCC coating thicknesses between 0.62 and 4.38 nm were fabricated as novel, efficient, and magnetically recyclable photocatalysts via a facile, green approach. The CoFe2O4/HTCC composites showed high magnetization and low coercivity, which favored magnetic separation for reuse. The results show that the close coating of HTCC on CoFe2O4 nanoparticles enhanced electron transfer and charge separation, leading to a significant improvement in photocatalytic efficiency. The composites exhibited superior photocatalytic inactivation toward Escherichia coli K-12 under visible-light irradiation, with the complete inactivation of 7 log10 cfu·mL–1 of bacterial cells within 60 min. The destruction of bacterial cell membranes was monitored by field-effect scanning electron microscopy analysis and fluorescence microscopic images. The bacterial inactivation mechanism was investigated in a scavenger study, and •O2, H2O2, and h...

Enhanced Visible-Light-Driven Photocatalytic Bacterial Inactivation by Ultrathin Carbon-Coated Magnetic Cobalt Ferrite Nanoparticles

Synthesis of high magnetization hydrophilic magnetite (Fe3O4) nanoparticles in single reaction—Surfactantless polyol process

In this research, structural, magnetic properties and photocatalytic activity of cobalt ferrite spinel (CoFe2O4) nanoparticles were studied. The samples were characterized by X-ray powder diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmission electronic microscopy (TEM), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), and UV-visible diffused reflectance spectroscopy (DRS) analysis. The XRD analysis revealed the formation of the single-phase CoFe2O4 with a cubic structure that is annealed at 500–700 °C in 3 h. The optical band gap energy for CoFe2O4 was determined to be in the range of 1.57–2.03 eV. The effect on the magnetic properties of cobalt ferrites was analyzed by using a vibrating sample magnetometer (VSM). The particle size and the saturation magnetization of cobalt ferrite nanoparticles increased with increasing annealing temperature. The photocatalytic activity of CoFe2O4 nanoparticles was investigated by using rhodamine B dye under visible light. The decomposition of rhodamine B reached 90.6% after 270 min lighting with the presence of H2O2 and CF500 sample.

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CoFe2O4 Nanomaterials: Effect of Annealing Temperature on Characterization, Magnetic, Photocatalytic, and Photo-Fenton Properties

Synthesis of CoFe2O4 powders with high surface area by solution combustion method: Effect of fuel content and cobalt precursor

The spinel structured cobalt ferrite (CoFe2O4) nanoparticles were successfully synthesized by sol-gel auto combustion method using three different fuels (Ethylene glycol, Glycine and Urea) approach. Pure phase formation of cobalt ferrite with cubic spinel structure was observed for all the samples in X-ray diffraction patterns. The average crystallite size, lattice parameter and other structural parameters were calculated from XRD data. The lower value of average particle size of 15 nm was noticed with urea as fuel. The sponge-like spherical shaped morphology was observed irrespective of the fuels. The average grain size was found to be in the range of 65–86 nm. The enhanced saturation magnetization, coercivity and other magnetic parameters obtained by M-H plots confirmed the superparamagnetic behaviour of the samples. It is observed from experimental results that using urea as a fuel one can obtain smaller particle size while the improved magnetic properties were observed for ethylene glycol as a fuel.

Sol-gel auto combustion synthesis and characterizations of cobalt ferrite nanoparticles: Different fuels approach

Microwave absorption studies of (Ba0.5Sr0.5Fe12O19)1-x/(NiFe2O4)x hard/soft ferrite nanocomposites

Analysis of the role of M-type hexaferrite-based materials in electromagnetic interference shielding

Single crystals of γ-glycine in the presence of cesium chloride were grown from aqueous solution by low temperature solution growth technique. The phase purity and crystal structure of the grown crystals were confirmed by Powder X-ray diffraction analysis. The presence of functional groups were confirmed by FT-IR spectrum. Thermal analysis of the grown crystal was determined by thermogravimetric and differential thermal analysis (TG/DTA), which results the thermal stability of the grown crystal. The optical absorption and lower cut-off values were ascertained by recorded UV-Visible spectrum of γ-glycine crystals. The existence of second harmonic generation efficiency of frequency doubling was found to be 6 times greater than that of KDP.

Effect of cesium chloride addition on crystal growth, structural, thermal and optical properties of γ‐glycine single crystal

Synthesis, growth, optical and mechanical studies of ferroelectric urea-oxalic acid single crystals

Organic bulk single crystal of cyclohexylaminium hydrogen phthalate hemihydrate (CYHPH) was grown by slow cooling method using methanol as a solvent. The grown crystal belongs to orthorhombic system with Pbcn space group and it has various functional groups such as NH3
 +, phthalate and a water molecule. The cut off wavelength of CYHPH was found at 307 nm. Thermal analysis affirmed that the CYHPH compound was stable up to 146 °C and completely decomposed at 263 °C. The activation energy at 100 Hz, 1 and 10 KHz was found to be 0.31, 0.141 and 0.142 eV respectively. The grown CYHPH crystal exhibits third order nonlinear optical behavior.

D. Rajan Babu

Papers

Microwave absorption studies of (Ba0.5Sr0.5Fe12O19)1-x/(NiFe2O4)x hard/soft ferrite nanocomposites

Analysis of the role of M-type hexaferrite-based materials in electromagnetic interference shielding

Effect of cesium chloride addition on crystal growth, structural, thermal and optical properties of γ‐glycine single crystal

Synthesis, growth, optical and mechanical studies of ferroelectric urea-oxalic acid single crystals

Growth and characterization of cyclohexylaminium hydrogen phthalate hemihydrate nonlinear optical single crystals