Calcination‐Dependent Morphology Transformation of Sol‐Gel‐ Synthesized MgO Nanoparticles

Abstract

Sol‐gel synthesis is a widely accepted method of producing nanoparticles with high surface area‐to‐volume ratio and purity at relatively low temperatures. For metal oxide nanoparticle synthesis, sol‐gel maintains a good metal oxide composition with controlled chemical structure and the ability to fine‐tune morphology and size. Magnesium oxide (MgO) nanoparticles possess unique physicochemical characteristics that have enabled a wide range of applications from catalysis to disease treatment. The potential features of MgO nanoparticles are significantly affected by their shape and size. However, research investigating the thermo‐molecular mechanisms governing the size and shape formation of MgO nanoparticles during sol‐gel synthesis is limited. This study investigates the effect of sol‐gel synthesis conditions on the shape and size as well as other functional features of MgO nanoparticles. The results demonstrated that the size and shape alterations of MgO nanoparticles were dependent on changes in calcination temperature and also the presence of periclase phase along with their crystallinity and functional groups. TEM analysis showed the morphological evolution during the synthesis process from spherical to hexagonal and from hexagonal to rod shape. By varying the calcination temperature and gelling agent composition in sol‐gel synthesis, MgO nanoparticles with different size distributions and morphologies can be generated for various applications. The current study reveals that the gelling agent is responsible for sol‐gel phase formation which eventually affects the calcination temperature for the formation of morphologically different MgO nanoparticles.

Sol‐gel coupled ultrasound synthesis of photo‐activated magnesium oxide nanoparticles: Optimization and antibacterial studies

“…Jeevanandam et al [ 33 ] reported the presence of negatively charged oxide ions on the surface of MgO nanoparticles ranging from −11.4 to −21.4 mV. Since a similar synthesis method is used in this study, MgO nanoparticles are assumed to a possess negative charge.…”

“…The thermal degradation and calcination temperature used to obtain spherical‐shaped MgO nanoparticles were adapted from our previous study. [ 33 ] The flowchart for the sol‐gel couple ultrasonication synthesis of the MgO nanoparticles is illustrated in Figure 1. All the equipment involved in this experiment was cleaned thoroughly beforehand to prevent any contamination during sample preparation.…”

“…Thus, the light absorbance peak of MgO nanoparticles, which extends from UV (<400 nm) to the visible light range [38] Sol-gel Mg(CH 3 COO) 2 .4H 2 O, citric acid 25.4-78. 8 Jeevanandam et al [33] Sol-gel coupled ultrasound Mg(CH 3 COO) 2 .4H 2 O, citric acid 19.2-27.2 Wee [39] Sol (400-550 nm) justifies this trend. The results from the TEM and DRS analyses prove that the incorporation of ultrasonication during the synthesis process led to a narrower bandgap for visible light absorption.…”

Calcination‐Dependent Surface Defect Variation and Antibacterial Activity of Magnesium Oxide Nanoplates

“…Wang et al demonstrated that the Li doping could increase the concentration of surface defect, enhance the basicity of nanoplates, and then improve antibacterial activity of MgO . Furthermore, studies showed that calcination temperature played a key role in the size and crystallinity of MgO . High calcination temperatures ( T calc ≥700 °C) can change the defect properties of micro‐rod MgO and improve its antimicrobial activity .…”

“…[11] Furthermore, studies showed that calcination temperature played a key role in the size and crystallinity of MgO. [12] High calcination temperatures (T calc � 700°C) can change the defect properties of micro-rod MgO and improve its antimicrobial activity. [13] However, there is few report that study the effect of calcination temperature on surface defect and antibacterial activity of MgO nanoparticles.…”