LAUSR

Abstract A facile approach for fabrication of hollow mesoporous MgO nanospheres (HMMN) has been demonstrated. The employed protocol involves the coating of carbon spheres template with MgO nanoparticles, followed by the calcination in presence of air to remove the carbon core at elevated temperature. Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) have been used to characterize the sample. Brunauer-Emmett-Teller (BET) method reveals the specific surface area and the average pore diameter of hollow spheres as 55.1 m2/g and 8.19 nm, respectively. The composite exhibits excellent adsorptive capacity toward Congo red (CR) at room temperature. The adsorption reaches equilibrium within 70 min with the maximum adsorption capacity of 5000 mg/g which is, to the best of our knowledge, the highest reported value. Additionally, the regeneration by calcination shows that adsorbent has high adsorption performance and superb reusability. GRAPHICAL ABSTRACT