Mesoporous amino-functionalized HKUST-1(Fe) for rapid adsorption of aqueous trace mercury with regeneration ability

Trace Hg²⁺ posed a serious threat to water safety. However, adsorption materials that can remove low concentration of mercury from water are still needed to be developed. In this work, amino-functionalized HKUST-1(Fe) with mesopores structure was synthesized by a one-pot method for the adsorption of trace mercury in the aqueous environment. Favorable pore conditions were beneficial for the diffusion of Hg²⁺. The doping of Fe³⁺ improved the stability of the material, effectively inhibited the original metal ion leaching by 85.54 % decrease. In addition, NH₂-BDC, and EDTA introduced nitrogen-containing groups to provide numerous active sites which captured Hg²⁺ specifically. Under optimal conditions, based on the changes in the binding energies of -NH-and O-C=O, HKUST(Fe)-NH₂@EDTA removed 95.45 % of Hg²⁺ (the initial concentration as low as 10 μg L⁻¹) within 10 min, with a maximum adsorption capacity of 1206.62 mg/g. After four adsorption-desorption cycles, it was still capable of removing 85.94 % of Hg²⁺ with regeneration performance. Combined with the excellent selectivity and anti-interference, the composited realized the removal of Hg²⁺ in real water samples, which meet the drinking water standards. This study provided a theoretical basis for the rapid and efficient adsorption of trace mercury in water by novel nanomaterials.