Large-scale Synthesis of Low-dimension Un-doped Iron Oxide Nanoparticles by a Wet-Chemical Method: Efficient Photo-catalyst & Sensitive Chemi-sensor Applications
Bismuth telluride (Bi2Te3) systems containing 2%, 4%, and 8% of iron were prepared using a low temperature wet chemical method. Iron oxide nanoparticles were formed when the samples were heated in hydrogen at 250 °C for at least six hours. The samples were characterized by x-ray diffraction, magnetization, magnetic susceptibility, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and wet chemical analysis measurements. The nanoparticles of iron oxide were identified as γ-Fe2O3 with a particle size of ˜5 nm.
Wet chemical method was applied to prepare magnesium oxide nanoparticles using magnesium nitrate and sodium hydroxide as precursors in presence of starch as stabilizing agent. The XRD analysis of MgO nanoparticles showed the average particles size of crystallite as 12nm. SEM images also proved the crystalline nature of MgO nanoparticles. Antibacterial studies were done on gram positive (S. aureus) and gram negative (E.coli) bacteria using the above prepared nanoparticles by agar diffusion method. The zone of inhibition was found to more in S.aureus compared to E.coli. Since this method of preparation produced better yield in simple and cost effective way, it can be applied for large scale preparation of magnesium oxide nanoparticles.
The wide range of actual and potential applications of nanoparticles, highlight the necessity of a reliable production method for both quality and quantity of the products. Mechanical attrition is one of the first well-known techniques used to produce nanoparticles. However, these approaches
have been restricted to produce uniform particles below the critical size of 15 nm because of the attrition balance limit. This paper introduces the magnetite–silicate raw material of a Kiruna-type ore deposit as a novel precursor, which enables the production of small iron oxide nanoparticles
below the critical size by mechanical attrition. X-ray fluorescence (XRF), powder X-ray diffractometry (pXRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used for characterization of the precursor and obtained nanoparticles. The results indicate that the
particles with a mean diameter of 10.7(2.7) nm consist of mainly less than one crystallite. The significant size reduction below the attrition balance limit can be attributed to the quartz content of the raw material, which operated as supporting micro-balls for transferring the energy during
the milling process.
Microstructure and Magnetic Properties of Iron Oxide Nanoparticles Prepared by Wet Chemical Method