Study on the Mechanism and Directional Drive of Magnetically Driven Nanomotor for Highly Targeted Clearance of Cr(Ⅵ) in Wastewater

Abstract

In this study, the development of a novel and highly efficient magnetically driven Fe3O4@SiO2-PA nanomotor for the targeted removal of Cr(VI) ions from wastewater is reported. The synthesized nanomotors exhibited enhanced adsorption capacity due to the incorporation of primary amide modification, which provided strong complexing ability towards Cr(VI) ions. Furthermore, the effect of pH on the adsorption process indicated that an internal complexation reaction mainly controlled the adsorption mechanism. The efficiency of the developed nanomotors for targeted Cr(VI) adsorption was further investigated in actual wastewater experiments. The results showed that the magnetically driven nanomotors achieved a remarkable targeted adsorption efficiency of 19.98 mg/g, effectively reducing the concentration of Cr(VI) ions in the treated wastewater to an extremely low level of 0.02 mg/L. In addition, the self-motion behaviour of the Fe3O4@SiO2-PA nanomotors was observed using optical microscopy, resulting in self-motion with a maximum motion rate of 325.37 μm/s.

Keywords: Water treatment, Cr(VI) removal, Nanomotor, Magnetic drives