Studies on Photocatalytic Performance of MgO Nanoparticles Prepared by Wet Chemical Method

In the present article, we explore a cost-effective and an environmentally benign route to prepare magnesium oxide (MgO) nanoparticles through thermal decomposition of magnesium hydroxide (Mg(OH)₂) nanoparticles. Mg(OH)₂ nanoparticles were prepared using different solvents namely ethylenediamine (EDA) and triethanolamine (TEA) by wet chemical method, and subsequently the as-synthesized Mg(OH)₂ nanoparticles were calcinated at 400°C for 2 h in air to obtain MgO nanoparticles. XRD pattern revealed that as-synthesized Mg(OH)₂ nanoparticles are polycrystalline in nature with hexagonal structure, and after annealing it transforms to MgO nanoparticles with cubic structure. FTIR spectrum of as-synthesized Mg(OH)₂ nanoparticles indicated the OH⁻ antisymmetric stretching vibration of the Mg(OH)₂ and after annealing the sharp peak at 3686 cm⁻¹ disappears, which confirms the complete transformation of hexagonal Mg(OH)₂ to cubic MgO. SEM analysis showed the formation of interfused Mg(OH)₂ nanoflakes and coral-like hierarchical MgO nanostructure made up of stacked nanoflakes. Optical band gap energy of Mg(OH)₂ and MgO nanoparticles prepared using different solvent were estimated using UV–Vis DRS. Degradation of methyl orange was performed to investigate the photocatalytic activity of coral-like hierarchical MgO nanostructure. Results demonstrate that coral-like hierarchical MgO nanostructure possessing large surface area and porous morphology exhibited good photocatalytic degradation of methyl orange.