Effect of Gelling Agent and Calcination Temperature in Sol–Gel Synthesized MgO Nanoparticles

Abstract

Magnesium oxide (MgO) is a versatile metal oxide with wide applications in electrical, chemical and pharmaceutical industries. Preparation of nano-MgO helps to enhance key physicochemical properties for optimal performance in industrial applications. In the present work, MgO nanoparticles were synthesized by magnesium nitrate precursor in ethanol. Different gelling agents were employed to investigate potential variations in the crystallinity and thermal behavior of the sol–gel product to control the nanoparticle’s size distribution. The crystal and thermal characteristics of the synthesized MgO nanoparticles were studied using X-ray diffraction (XRD) and Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) analysis. The XRD data showed that all the samples demonstrated crystallinity except sample B which was amorphous. The TG-DSC characterization showed a three stage thermal decomposition for all the samples, leading to the formation of MgO nanoparticles. Based on the thermal analysis data, different calcination temperatures were selected to investigate their effects on stability, and the sample prepared with tartaric acid as a gelling agent and calcined at 500oC demonstrated the smallest average particle size of 58.7 nm obtained from dynamic light scattering (DLS) analysis. Further, this sample was subjected to XRD, FTIR and TEM analysis which reveals that the calcination yielded impure, 30 nm sized spherical shaped, agglomerated MgO nanoparticles. Additionally, the physicochemical characteristics of the selected sample reveals that pure MgO nanoparticles with uniform morphology can be obtained via alteration of calcination time and heating rate.