Interface-Constrained Layered Double Hydroxides for Stable Uranium Capture in Highly Acidic Industrial Wastewater.

Abstract

Low acid endurance of layered double hydroxides (LDHs) limits their uranium(VI) [U(VI)] adsorption capability from harsh industrial wastewater. Here, we demonstrate magnesium-cobalt LDHs (Mg-Co LDHs) anchored in situ onto the pore channel of dendritic fibrous nanosilica (DFNS) via an interface-constrained strategy. The synergy of Mg-Co LDHs and DFNS not only improves the endurance of the Mg-Co LDH under harsh acidic conditions but also increases the number of active sites of DFNS. Thus, DFNS@Mg-Co LDH shows a high U(VI) uptake capacity (1143 mg g-1) at pH = 3 and C0 = 598.7 mg L-1, which is about 4.8-fold higher than that of pristine DFNS. The DFNS@Mg-Co LDH exhibits excellent U(VI) uptake in various background water circumstances due to its acid endurance and highly selective adsorption. This interface-constrained strategy provides LDH materials with durability under extremely acidic conditions along with a high adsorption capacity, which is promising for uranium capture from various water fields.