Mesoporous nanocrystalline magnesium oxide for environmental remediation

Abstract

Mesoporous MgO nanocrystals are prepared through combustion route using magnesium nitrate as oxidizer and glycine as fuel. The powder has been characterized using powder X-ray diffraction (PXRD), scanning and transmission electron microscopy (SEM/TEM), surface area and porosity measurements. The PXRD pattern confirms the crystallinity and phase purity of the powder and the particle size obtained from Scherrer’s formula lies in the range 12–23 nm. The SEM result reveals that the powder is porous and agglomerated with polycrystallite nanoparticles. The pore diameter observed in TEM image is in the range 4–11 nm. The surface area of the powder is ∼107 m2/g and average pore diameter obtained from desorption is 7.8 nm. It is found that 0.15 g of as made MgO powder could remove 97% of fluoride from standard sodium fluoride solution (10 ppm) and 75% of fluoride from tube well water. In this technique 90% minimization of sludge could be achieved. The comparative studies on the fluoride removal capacity of as made, regenerated and commercial grade MgO powders are found to be 97%, 76% and 17%, respectively.