CTAB-assisted fabrication of hierarchical flower-like magnesium oxide adsorbent for enhanced removal performance towards phosphate

In this work, a series of hierarchical flower-like magnesium oxide (MgO) adsorbents were successfully fabricated in a cetyltrimethylammonium bromide (CTAB) assisted solvothermal route using hexamethylenetetramine (HMTA) as a precipitating agent. Effects of CTAB feeding amount on the structure, morphology, pore structure, and corresponding adsorption behavior were investigated. The hierarchical gardenias flower-like MgO demonstrated a surface area of 336.54 m2 g−1 at a minimum ratio of the CTAB/Mg2+ was 0.02 in the reaction system. The hierarchical MgO phosphate removal capacity was 348.32 mg g−1, which followed the pseudo-second-order and Freundlich isotherm model obtained from the large surface area and appropriate pore size. The value of n also suggests the feasible nature of phosphate adsorption under the examined conditions. Indeed, this CTAB assisted solvothermal method can provide a new understanding to tune the desired properties of a material by merely adjusting the reaction parameters of MgO.