UV - Sun light Photocatalytic and photoluminescence Studies of Rare-Earth-Doped (Sm 3+ ) MgO nanopowders by Aloe Vera gel (original) (raw)
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Microstructure, optical and photocatalytic properties of MgO nanoparticles
Results in Physics, 2020
The present work is focused on the synthesize of MgO nanoparticles using combustion method. The magnesium nitrate is used as a precursor with urea as a fuel. The precursor material is dissolved in 50 ml DI water along with the fuel and the solution is heated at 80°C for 2 h. Then, the solution is transferred to crucible and kept it in the temperature of 500°C. The as-synthesized MgO nanopowders are analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), photo-luminescence (PL) and photocatalytic studies. The XRD results of MgO nanoparticles indicated the cubic structure with the crystallite size of 27 nm. The FESEM studies indicated the formation of MgO crystallites in spherical shape. In addition, MgO nanoparticles are porous and agglomerated. PL spectrum of MgO materials exhibit emission peaks, which indicates the occurrence of band to band transition with the bandgap of 2.9 eV. The photocatalytic degradation of methylene blue dye is evaluated using the as-prepared MgO nanoparticles under UV light. The photocatalytic studies indicate the 75% degradation efficiency of the catalyst after 120 min irradiation. Hence, the MgO Nanoparticles (NPs) can be used for the treatment of effluents from the dye industries .
Photocatalytic Studies of MgO Nano Powder; Synthesized by Green Mediated Route
Materials Today: Proceedings, 2018
MgO nano powders were synthesized by a bio mediated route. The obtained products were characterized by powder X-ray diffraction (PXRD), diffuse reflectance spectroscopy (DRS) Scanning electron microscope (SEM), Transmissionelectron Microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). PXRD patterns show hexagonal single cubic phase MgO matched with JCPDS Card No 78-0430. The crystallite size obtained from TEM was found to be ~ 15-20 SEM result reveals porous nature of the obtained nano-powder. The optical energy gap is 3.20eV which demonstrates that there is a movement to the higher wavelengths of the absorption edge with reduction of the energy gap when using green fuel for synthesis. The photocatalytic studies relatively high activity for degradation of Malachite Green (MG) and Rhodamine-B (Rh-B) under sunlight irradiation compared to UV light. The good structure and excellent performance of ZnO nano-composites, suggest its promising application in dye decolarization.
Photoluminescence and photocatalytic activity of MgO powders
Materials Chemistry and Physics, 1988
Nanocrystalline ZnO particles doped with Mn(II) ions were prepared by a forced hydrolysis method of zinc acetate dihydrate and manganese acetate tetrahydrate, under reflux, in buthanol. The precipitate obtained was separated by centrifugation at 9.000 rpm and purified by refluxing in water. The dopant percentage was 1, 2.5 and 5%. The qualitative composition of the nanopowder has been evidenced in the elemental EDS maps. Optical investigation shows that the Mn doping in ZnO lattice leads to a decrease in the near band edge position due to the introduction of new unoccupied states by Mn 3d electrons. The luminescence of ZnO is quenched by increasing the dopant ions percentage. At doping rate of 1% Mn in the ZnO lattice a tenfold decrease in intensity of luminescence was observed, along with modification of the luminescence pattern. Further increases of dopant percent from 1% to 5% had as result a decrease of only 30% in the luminescence intensity. The photocatalytic activity was investigated against methylene blue. The increase of Mn percentage leads to a better photocatalytic activity.
Physica B: Condensed Matter, 2020
In the current study, pure MgO nanostructures in the presence of Oleic acid (OA) with 0.2 cc , 0.4 cc , 0.6 cc , 0.8 cc and 1 cc as a capping agent were successfully prepared using the ultrasound-assisted method. The effect of the OA concentration on the structural, morphological, optical and porosity properties of prepared nanocomposite materials were studied by Thermogravimetric-differential thermal analysis (TGA-DTA), Field Emission Scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), UV-Vis spectra and BET (Brunauer, Emmett and Teller). Photocatalytic activity of MgO and OA-doped MgO nanostructures were checked by the degradation of methylene blue (MB) under visible light at optimum pH value. Obtained results show that between samples with different concentrations of OA, the MgO-0.6 cc OA nanostructures showed the highest degradation performance and decompose 99% of MB at 25 min.
Journal of Chemistry
The magnesium oxide nanoparticles (MgO NPs) were prepared from Moringa oleifera leaf extract. Phytochemicals are derived from plant extract which are served as stabilizing and capping agents. This green route has been attracted owing to speed, reliable, and eco-friendly and cost-effective one. The synthesized magnesium oxide nanoparticles were taken into three different calcination temperatures (500, 600, and 700°C). The powder X-ray diffraction (PXRD) study shows a pure phase of face-centered cubic structure. Periclase MgO nanoparticles were prepared. The optical band gap of MgO nanoparticles is 4.5 eV, and its absorption in the UV region was observed by UV-visible spectroscopy (UV-Vis). Photoluminescence spectra have exhibited multicolor emissions were being at UV and visible region due to defect centers (F centers) of MgO nanoparticles. EDX (energy dispersive X-ray spectrum) has given the stoichiometric ratio of Mg and O. The functional groups have been studied by Fourier transfo...
Oriental Journal of Chemistry
MgO nanoparticle was synthesized by sol-gel method from magnesium acetate and oxalic acid dissolved in methanol followed by annealed process. Characterization of functional groups was performed using (FTIR) Fourier Transforms Infrared spectroscopy, crystal profile analysis using (XRD) X-ray Diffraction and morphology using (SEM) Scanning Electron Microscopy. The FTIR and XRD results indicated that the magnesium acetate converted into magnesium oxalate (Precursor), and then the anneal process was changed into MgO nanoparticles. The Scherrer's equation used to determine the distribution of MgO nanoparticle crystals. Modified Williamson-Hall plot is used to determine the strain, stress and energy density value (micro structural properties) based on angle values 2θ and (FWHM) Full width at half maximum of XRD angles from 10° to 80°. The results of the XRD and SEM analysis show that magnesium complexes have changed. The solid layer formed by the Mg polymer complex network is transformed into a cubic structure.
Optik, 2018
A simple solution combustion method was adopted to form a series of MgO nanophosphors doped with different mol% of Dy 3+ ions using urea as a fuel. The powder products were well characterized structurally, morphologically and optically by Powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and diffuse reflectance spectra. The elemental confirmation was done through elemental analysis by energy dispersive X-ray spectroscopy (EDX). The XRD patterns show that the final product is cubic in shape with the crystallite size ranging from 25-44 nm along with strain and dislocation densities also supported by HRTEM analysis. Photoluminescence (PL) studies under identical experimental conditions for the UV excitations, the formation of three prominent emission spectra at 488, 590 and 630 nm has been observed. These spectra show the transitions of 4f→6h energy levels, namely 4 F9/2→ 6 H15/2 (488 nm), 4 F9/2→ 6 H13/2 (590 nm) and 4 F9/2→ 6 H11/2 (630nm). The afterglow decay curve shows the single exponential decay for different MgO:Dy 3+ nanophosphors compositions have been studied in detail.
GROWTH MECHANISMS OF MgO NANOCRYSTALS VIA A SOL-GEL SYNTHESIS USING DIFFERENT COMPLEXING AGENTS
MgO thin films have been prepared on substrates by a novel and simple sol-gel method using magnesium nitrate and collusion as starting material. The MgO nano catalyst with good sensor crystallization were obtained after annealing at 100°C Magnesium oxide was prepared by sol-gel method. The method involves the hydrolysis of magnesium alkoxide in the presence of acid or basic catalysts followed by a polyethylene glycol condensation reaction. The synthesized solids were characterized by IR spectroscopy X-ray diffraction electron microscopy, Ultraviolet visible absorbance measurement photoluminescence and Raman scattering spectra. sol gel irradiation the structure and morphology of the MgO particles were analyzed by XRD,These articles were used for FTIR spectroscopic measurement and spectra were collected, In EDS we calculated the peak intensity the SEM the images of metal oxide.
Enhanced Photocatalytic Decomposition Efficacy of Novel MgO NPs: Impact of Annealing Temperatures
Journal of Inorganic and Organometallic Polymers and Materials, 2021
The magnesium oxide (MgO) nanoparticles (NPs) were prepared using the sol-gel method and the prepared nanoparticles were annealed at different temperatures (500, 600, and 700 °C). The prepared nanoparticles were characterized using X-ray diffraction (XRD) for the structural analysis (Rietveld refinement), SEM for surface morphological analysis, and the energy dispersive X-ray analysis for elemental compositional analysis. The detailed structural analyses proved the expansion of the unit cell by increasing the annealing temperature. The detailed electronic bonding behavior and the expansion of the unit cell of the prepared nanoparticles were analyzed and reported using the maximum entropy method (MEM). The light absorption behavior of the MgO was probed using UV-Vis-NIR spectroscopic analysis. The photocatalytic decomposition capabilities of the synthesized MgO nanoparticles were studied against a model pollutant such as methylene blue dye. The maximum photocatalytic efficiency of 92% in 150 min was observed for MgO nanoparticles annealed at 700 °C.