Cu/Al2O3 aerogels for high-efficiency and rapid iodide elimination from water

Cu-based functional materials are excellent candidates for the elimination of iodine anions. However, the low utilization rate of Cu and its unsatisfactory adsorption performance limit its large-scale practical applications. This paper proposes a co-gelation method to obtain Cu/Al 2 O 3 aerogels with a high specific area (537 m 2 /g). Cu/Al 2 O 3 aerogels have a hierarchical porous structure and contain a high proportion of Cu (20.5 wt%). The high dispersibility of Cu, which is based on an in-situ gel process, provides conditions for the high-efficiency elimination of iodide anions. We conducted adsorption experiments that demonstrated that the fabricated Cu/Al 2 O 3 aerogel had an ultrahigh adsorption capacity (407.6 mg/g) and a fast adsorption equilibrium time (0.5 h) for iodide anions. Additionally, the Cu/Al 2 O 3 aerogel could selectively capture iodine anions even in the presence of high concentrations of competing ions (NO 3 - , SO 4 2- , and Cl - at 60 mmol/L). Importantly, the aerogel can operate in a wide pH range of 3–11 without causing secondary pollution. This work demonstrates that low-cost Cu/Al 2 O 3 aerogels exhibit great potential for eliminating radioactive iodine anions.