Fabrication of surface ion imprinting rice husk-based polymer for selective detection and efficient adsorption of Cu2+ in lake water

Abstract

With the deepening of the concept of recycling economy and green chemistry, selective detection and capture of Cu2+ from lake water by biosorbent are of great significance. Herein, the Cu2+ ion-imprinted polymers (RH-CIIP) with organosilane containing hydroxyl and Schiff base groups (OHSBG) as ion-receptor, fluorescent chromophores and cross-linking agent, and Cu2+ as template ion, were fabricated via surface ion imprinting technology by employing mesoporous silica MCM-41 (RH@MCM-41) as supporter. The RH-CIIP could be exploited as a fluorescent sensor for Cu2+ with high selective compared with Cu2+ non-imprinted polymers (RH-CNIP). Additionally, the LOD was calculated to be 5.62 μg/L, which is far below WHO standard for Cu2+ in drinking water of 2 mg/L, and more lower than the reported methods. Moreover, the RH-CIIP can also be utilized as an adsorbent for the effective elimination of Cu2+ from lake water with the adsorption capacity of 87.8 mg/g. Besides, the kinetic features of adsorption were well defined by the pseudo-second-order model and the sorption isotherm was in agreement with the Langmuir model. Meanwhile, the interaction of RH-CIIP and Cu2+ was investigated using theoretical calculations and XPS. Finally, RH-CIIP was able to remove almost 99 % Cu2+ in lake water samples that satisfied the drink water standard.