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

With the deepening of the concept of recycling economy and green chemistry, selective detection and capture of Cu from lake water by biosorbent are of great significance. Herein, the Cu ion-imprinted polymers (RH-CIIP) with organosilane containing hydroxyl and Schiff base groups (OHSBG) as ion-receptor, fluorescent chromophores and cross-linking agent, and Cu 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 Cu with high selective compared with Cu non-imprinted polymers (RH-CNIP). Additionally, the LOD was calculated to be 5.62 μg/L, which is far below WHO standard for Cu 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 Cu 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 Cu was investigated using theoretical calculations and XPS. Finally, RH-CIIP was able to remove almost 99 % Cu in lake water samples that satisfied the drink water standard.