Synthesis of Porous Hierarchical MgO and Its Superb Adsorption Properties

The porous hierarchical MgO with superb adsorption properties has been synthesized by a facile and scaled-up method. The X-ray powder diffraction, electron microscopy, Fourier transformed infrared, and N2 adsorption–desorption were carried out to study the microstructure of the as-synthesized precursor and product. It has been demonstrated that the as-prepared MgO has a porous hierarchical structure and a high specific surface area (148 m2 g–1). And the MgO sample exhibited super adsorption properties, with maximum adsorption capacity of 2409 mg g–1 for Congo red, which is the highest reported value. Moreover, the adsorption process of Congo red on porous hierarchical MgO was systematically investigated, which was found to obey the pseudo-second-order rate equation and Langmuir adsorption model.