Morphologically controlled synthesis of ferric oxide nano/micro particles and their catalytic application in dry and wet media: a new approach

Mössbauer spectroscopic investigations on iron oxides and modified nanostructures: A review

Pure and doped iron oxide and hydroxide nanoparticles are highly potential materials for biological, environment, energy and other technological applications. On demand of the applications, single phase as well as multiple phase of different polymorphs or composites of iron oxides with compatible materials for example, zeolite, SiO₂, or Au are prepared. The properties of the as-synthesized nanoparticles are predominantly dictated by the local structure and the distribution of the cations. Mössbauer spectroscopy is a perfect and efficient characterization technique to investigate the local structure of the Mössbauer-active element such as Fe, Au, and Sn. In the present review, the local structure transformation on the optimization of the magnetite coexisted with iron hydroxides, spin dynamics of the bare, caped, core-shell and the composites of iron oxide nanoparticles (IONPs), dipole-dipole interactions and the diffusion of IONPs were discussed, based on the findings using Mössbauer spectroscopy.

Synthesis of Magnetic Fe3O4 Nano Hollow Spheres for Industrial TNT Wastewater Treatment

The aim of the present work was to synthesize magnetite (Fe3O4) nano hollow spheres (NHS) via simple, one-pot, template-free, hydrothermal method. The structural, morphological, and surface analysis of Fe3O4 NHS were studied by scanning electron microscopy (SEM), x-ray diffraction technique (XRD), Fourier transform infrared spectroscopy FTIR and burner-Emmett-teller (BET). The as obtained magnetic (Fe3O4) NHS were used as an adsorbent for treating industrial trinitrotoluene (TNT) wastewater to reduce its Chemical Oxygen Demand (COD) values. Adsorption capacity (Qe) of the NHS obtained is 70 mg/g, confirming the attractive forces present between adsorbent (Fe3O4 NHS) and adsorbate (TNT wastewater). COD value of TNT wastewater was reduced to >92% in 2 h at room temperature. The adsorption capacity of Fe3O4 NHS was observed as a function of time, initial concentration, pH, and temperature. The applied Fe3O4 NHS was recovered for reuse by simply manipulating its magnetic properties with slight shift in pH of the solution. A modest decrease in Qe (5.0−15.1%) was observed after each cycle. The novel Fe3O4 NHS could be an excellent candidate for treating wastewater generated by the intermediate processes during cyclonite, cyclotetramethylene-tetranitramine (HMX), nitroglycerin (NG) production and other various environmental pollutants/species.

Photocatalytic degradation of reactive black 5 on the surface of tin oxide microrods

A simple co-precipitation technique is proposed for synthesis of tin oxide (SnO₂) microrods. Stannous chloride and urea were used during synthesis. X-ray powder diffraction (XRD) analysis revealed that the annealed product consists of SnO₂ microrods having tetragonal unit cells, while scanning electron microscopy (SEM) analysis revealed the rod-like morphology of a synthesized product. These synthesized microrods are used as photocatalyst for the degradation of reactive black 5 (RB5). Degradation kinetics of RB5 are monitored under daylight in different concentrations of hydrogen peroxide (H₂O₂) and catalyst. The percentage of RB5 conversion is also calculated at various concentrations of hydrogen peroxide and catalyst which demonstrate that RB5 shows high catalytic degradation at high concentrations of hydrogen peroxide and catalyst.