Pardeep Singh; Sourav Gautam; Pooja Shandilya; Bhanu Priya; Virender P. Singh; Pankaj Raizada
Abstract
The supported photocatalysis is emerging as an effective technology to overcome of inherent drawbacks of bare magnetic photocatalysts. Herein, ZnFe2O4 was immobilized over graphene sand composite (GSC) and bentonite (BT) to report ZnFe2O4/GSC and ZnFe2O4/BT photocatalyst. The size of ZnFe2O4/GSC and ...
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The supported photocatalysis is emerging as an effective technology to overcome of inherent drawbacks of bare magnetic photocatalysts. Herein, ZnFe2O4 was immobilized over graphene sand composite (GSC) and bentonite (BT) to report ZnFe2O4/GSC and ZnFe2O4/BT photocatalyst. The size of ZnFe2O4/GSC and ZnFe2O4/BT was obtained as 100 and 50 nm, respectively. Both photocatalysts exhibited band gap of 1.95 eV. ZnFe2O4/GSC and ZnFe2O4/BT had BET surface area of 15.6 and 14.5 cm 2 , respectively. The appearance of D and G band in Raman spectra indicated the formation of graphene sand composites. The superparamagnetic property of photocatalyst resulted in quick separation photocatalyst form reaction solution. The adsorption and photocatalytic capability of ZnFe2O4/GSC and ZnFe2O4/BT was evaluated for photo-mineralization of ampicillin and oxytetracycline antibiotics. The adsorption process showed significant effect on mineralization of selected antibiotics. Simultaneous adsorption and degradation (A+P) process was highly effective for antibiotic degradation. More than 90% of antibiotic mineralization was obtained in 10 hours. The power law model authorized the complex nature of degradation process. Magnetically recoverable photocatalyst exhibited significant recycling efficiency due to easier recovery of photocatalysts.
Virender P. Singh; Gagan Kumar; Pooja Dhiman; R. K. Kotnala; Jyoti Shah; Khalid M. Batoo; M. Singh
Abstract
In the present work BaFe12O19 nano-hexaferrite had been synthesized by sol-gel method and then characterized for its structural, electric, dielectric and magnetic properties. X-ray diffraction studies confirmed the hexagonal structure of the prepared nanohexaferrite with no secondary phase and the particle ...
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In the present work BaFe12O19 nano-hexaferrite had been synthesized by sol-gel method and then characterized for its structural, electric, dielectric and magnetic properties. X-ray diffraction studies confirmed the hexagonal structure of the prepared nanohexaferrite with no secondary phase and the particle size was found to be of the order of 49 nm. Further, the morphology of the sample has been studied by using transmission electron microscopy (TEM). A high value of the DC resistivity (5.5 × 106 Ω cm), has been obtained at room temperature. The dielectric properties such as dielectric constant (ε′), dielectric loss tangent (tan δ) and ac electrical conductivity (σac) are investigated as a function of frequency. The dielectric constant and loss tangent are found to be decreasing with the increase in frequency while ac electrical conductivity is observed to be increasing with the increase in frequency. The dielectric properties have been explained on the basis of Maxwell-Wagner’s two-layer model and hopping of the charge. The magnetic properties such as initial permeability (µi) and relative loss factor (RLF) have been investigated as a function of frequency in the range 75 kHz to 30 MHz .Fairly constant value of initial permeability and low values of RLF of the order of 10-4 over a wide frequency range are the cardinal achievements of the present work. The room temperature M-H study shows that present nanohexaferrite has high value of coercivity (2151.3 Oe) and high saturation magnetization (32.5 emu/gm), which make present nanohexaferrite very suitable for magnetic applications. The M-T study shows that prepared nano-hexaferrite has high Tc (746 K).
