Fly ash-derived mesoporous silica foams for CO2 capture and aqueous Nd3+ adsorption.

Graphical abstract Abstract A supernatant solution of the silicate species extracted after alkali fusion of the acid-treated power plant fly ash was used to prepare mesoporous silica foams (MSF S) in acidic condition, where Pluronic P123 and trimethylbenzene (TMB) were used as the structure directing agent and swelling agent, respectively. The MSF was impregnated with polyethyleneimine (PEI) up to 63.2 wt.%, which exhibited CO 2 adsorption capacity of 4.7 mmol/g adsorbent at 75 °C, 1 bar. Additionally, the MSF after ethylenediaminetetraacetic acid (EDTA) functionalization showed the Nd³⁺ adsorption capacity of 117 mg/g at the optimal pH of 6, with sufficiently fast kinetics and good recyclability. [ABSTRACT FROM AUTHOR]