Bioinspired zeolitic imidazolate framework (ZIF-8) magnetic micromotors for highly efficient removal of organic pollutants from water

This paper reports the first proof-of-concept of using bioinspired ZIF-8 based micromotors for efficient water remediation. Natural kapok fibers have unique hollow structure that contains cellulose and lignin, inspiring the design and fabrication of bubble-driving tubular micromotors as an active self-propelled micromachine for the removal of organic pollutants from water. The outer dense ZIF-8 layer can adsorb organic pollutants on the micromotors, and the inner catalyst acts as the engine decomposing fuel H2O2 for providing bubble propulsion. The magnetic gamma-Fe2O3 enables the external magnetic control movement and recovery of micromotors. The maximum adsorption capacity of ZIF-8-based magnetic micromotors toward Congo red and doxycycline were high as 394 and 242 mg g(-1), respectively, mainly due to the enhanced micromotor-pollutant contacts by their autonomous motion and the resulting mixing associated effect. This novel ZIF-8 micromotor also showed outstanding stability and reusability in aqueous solution, indicating that their great potential for future application in water treatment. (C) 2019 Elsevier Inc. All rights reserved.