Controllable Fabrication of Mesoporous MgO with Various Morphologies and Their Absorption Performance for Toxic Pollutants in Water

We have developed a method of controllable synthesis of MgO with various morphologies by adjusting the composition and phase structure of magnesium carbonate hydrate (MCH). The phase structure of the MCH varied from monoclinic Mg 5 (CO 3 ) 4 (OH) 2 (H 2 O) 4 to hexagonal MgCO 3 by changing the concentration of Mg 2+ and HCO 3 −; the corresponding morphology of the MCH ranges from nanoflakes and flowerlike microspheres composed of nanoflakes to layer-like rhombohedra and microspheres composed of rhombohedra. After annealing, four kinds of mesoporous cubic MgO micronano structures were obtained with their original morphologies. Because of the high specific surface area, MgO mesoporous nanoflakes and flowerlike microsphers exhibited excellent absorption performance for common toxic heavy metal ions and organic pollutants and are expected to be a potential absorbent in wastewater treatment.