Comparative Study of Structural, Morphological, Magneto-Optical and Photo-Catalytic Properties of Magnetically Reusable Spinel MnFe₂O₄ Nano-Catalysts

Abstract

Spinel MnFe2O4 nanostructures were synthesized by simple, economical and eco-friendly microwave combustion (MCM) and conventional combustion (CCM) methods using metal nitrates and glycine used as the fuel, instead of toxic inorganic/organic catalyst, template and surfactant. Powder XRD and FT-IR, EDX and SAED results were confirmed the products have a cubic phase spinel structure. EDX and SAED results confirmed purity and high crystallinity without any other secondary phase impurities. HR-SEM and HR-TEM analysis indicate that the MCM and CCM products consist of nano- and microstructures, respectively. The optical band gap (Eg) was measured using Kubelka-Munk model and it shows higher value (2.37 eV) for MnFe2O4-MCM than MnFe2O4-CCM (2.15 eV), due to the smaller particle size of MnFe2O4-MCM. VSM results showed a superparamagnetic behavior and the magnetization (Ms) value of MnFe2O4-MCM is higher i.e., 39.68 emu/g than MnFe2O4-CCM (33.59 emu/g). It was found that the sample MnFe2O4-MCM have higher surface area than MnFe2O4-CCM, which in turn leads to the improved performance towards the photocatalytic degradation (PCD) of methylene blue (MB) and it was found that the sample MnFe2O4-MCM show higher PCD efficiency (96.48%) than MnFe2O4-CCM (84.95%). Also, MnFe2O4 show higher activity with good reusability, and eco-friendly materials for industrial and technological applications.

Removal of Organic Dyes from Water and Wastewater Using Magnetic Ferrite-Based Titanium Oxide and Zinc Oxide Nanocomposites: A Review

“…This was attributed to the presence of a narrow band gap energy (1.95 eV) of MnFe2O4/ZnO. Silambarasu et al [108] tested the performance of MnFe2O4 on the degradation of methylene blue dye. The manganese ferrite achieved 96% dye decolorization and exhibited saturation magnetization (Ms) of 39.7 emu/g.…”

Spinel ferrite of MnFe2O4 synthesized in Piper betle Linn extract media and its application as photocatalysts and antibacterial

“…[4] MnFe 2 O 4 was also prepared by electrochemical/chemical for electrode, [11] by thermal decomposition for degradation of phenol in the presence peroxydisulfate, [12,13] by solution combustion method for antibacterial and photocatalytic process, [1,9] by microwave and conventional combustion, and by microwave irradiation technique for photocatalytic degradation of methylene blue dye. [14,15] Each of these methods has its advantages and limitations. However, there was no report about the synthesis of MnFe 2 O 4 by a hydrothermal method in natural extract media and applied as a catalyst for Direct Red 81 dye degradation and antibacterial agent.…”

Crack-tip plasticity and intrinsic toughening in nano-sized brittle amorphous carbon

“…While there have been a number of studies investigating electronic (Fischetti et al, 2002;Kato et al, 2004;Minot et al, 2003;Mkhoyan et al, 2009;Ruffieux et al, 2012), magnetic (Akbarzadeh et al, 2012;Jiang et al, 2015;Li et al, 2011;Reddy et al, 2012;Saha et al, 2019), plasmonic (Boltasseva and Shalaev, 2015) and optical properties (Aumer et al, 2000;Jacobsen et al, 2006;Kuznetsov et al, 2016;Silambarasu et al, 2018;Yang et al, 2002) of ceramic nanomaterials, the importance of mechanical performances focused on deformation, fracture, and failure has been relatively underestimated. However, to assure the reliable operation and prolonged lifetime of such engineering systems under various loading and straining conditions, it is of great importance to understand the fundamental mechanical deterioration mechanisms, e.g., fracture, that impair the integrity and performance.…”