Engineered Multi-Shelled hollow mesoporous organosilica for efficient Pb(II) and Cr(VI) removal

Adsorbents with fast kinetics and high capacity have always been attractive for wastewater treatment. Herein, multi-shelled hollow mesoporous organosilica functionalized by hydroxyphosphatoethyl groups on dual-pore surfaces (P-HMO) is prepared by general one-pot co-condensation. The resulting P-HMO exhibits high hydrophilicity, large surface area and well-developed pore structure, providing P-HMO fast adsorption kinetics (C0 = 320 mg·L-1, equilibrium within 5 min) and ultrahigh adsorption efficiency for Pb(II) and Cr(VI), the adsorption capacity reaches 1056.53 and 869.56 mg·g−1, respectively. Furthermore, P-HMO displays outstanding reusability over 10 adsorption–desorption cycles thanks to the stable framework structure that can resist wear and tear during water treatment. The advantages of long service life, high efficiency and broad pH range make P-HMO promising in industrial water purification.