▎ 摘　　要

Herein, we have developed an easy method for the fabrication of hollow three-dimensional (3D) graphene oxide/MnFe2O4 (GO/MnFe2O4) motors by mediating GO suspension with aniline and MnFe2O4 via coupling shear force with capillarity. It is found that shear force helps the size breakup of GO/MnFe2O4 hydrogels and the formation of turbulent flow structures during their assembly. Furthermore, capillarity further shrinks their sizes and produces an asymmetric hollow Janus-like GO/MnFe2O4 motor at the millimeter scale during the drying process. In addition, the GO/MnFe2O4 motor demonstrates high efficiency as an adsorbent for the removal of heavy metals (i.e., Pb2+ and Cd2+) because of the rich oxygen-containing groups of GO. MnFe2O4 enables external magnetic control and functions as an engine decomposing H2O2 fuel for bubble-driven movement of motors in the target area. Typically, 20 mg GO/MnFe2O4 motor can fully remove 100 mg L-1 Pb2+ and Cd2+ in 150 min and 180 min, respectively. Furthermore, the motor can be reused and retains 99.8% adsorption efficiency in the fifth cycle after chemical detachment of Pb2+ and Cd2+ with 0.2 M HCl from the surface of GO/MnFe2O4.