Fabrication of three-dimensional ordered macroporous/mesoporous magnesium oxide for efficient cadmium removal

Cadmium (Cd) is a hazardous heavy metal, that poses a serious threat to human health. Magnesium oxide has shown excellent adsorption performance for the removal of Cd(II) from contaminated wastewater. Herein, three-dimensional ordered macroporous/mesoporous MgO (3DOM/m MgO) was synthesized by a double template method using amphiphilic triblock copolymer Pluronic F127 as the soft template and polystyrene colloidal crystal as the hard template. Compared with three-dimensional ordered macroporous MgO (3DOM MgO), 3DOM/m MgO exhibited a macro/mesoporous structure with a larger specific surface area (96.94 m(2)/g). The maximum adsorption capacity of 3DOM/m MgO reached 2933 mg/g for the removal of Cd(II) removal from an aqueous solution. BET and XPS analyses results revealed that the enhanced Cd(II) adsorption capacity of 3DOM/m MgO was attributed to its large specific surface area and the complexing ability of its hydroxy groups. The adsorption performance of 3DOM/m MgO was investigated by batch adsorption experiments, including adsorption isotherms and adsorption kinetics. 3DOM/m MgO completely removed 100 mg/L Cd(II), with a removal efficiency >= 99.9%. The adsorption behavior followed the pseudo-second-order kinetic model and Langmuir isotherm model, which revealed that the adsorption of Cd(II) on 3DOM/m MgO proceeded via homogeneous chemisorption. Due to its advantages of controllability and excellent adsorption performance, 3DOM/m MgO is a promising adsorbent for the removal of Cd(II) from polluted water.

Automated summary

In this study, three-dimensional ordered macroporous/mesoporous MgO was synthesized and showed high adsorption capacity for Cd(II) removal. Batch adsorption experiments confirmed the efficient removal of Cd(II) from water using this material.