1. Self-assembly of a graphene oxide/MnFe2O4 motor by coupling shear force with capillarity for removal of toxic heavy metals
- Author
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Jiaxin Zhao, Hongbo Fan, Jielan Li, Jiangying Qu, Peng Xiyue, and Feng Gao
- Subjects
Materials science ,Fabrication ,Renewable Energy, Sustainability and the Environment ,Graphene ,Shear force ,Oxide ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemical engineering ,law ,Coupling (piping) ,General Materials Science ,Self-assembly ,0210 nano-technology ,Suspension (vehicle) - Abstract
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 MnFe2O4via 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.
- Published
- 2018
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