A novel bio-template route to synthesize enzyme-immobilized MOF/LDH tubular magnetic micromotors and their application in water treatment

Abstract

Micromotors capable of autonomous movement, sensitive detection and rapid removal of pollutants have attracted wide attention in environmental monitoring and water pollution remediation. In this paper, a ramie-derived hierarchical MgAl-LDH/MFZ@HRP magnetic microtube micromotor with peroxidase activity was proposed for simultaneous detection and removal of catechol from water. The Mn₂O₃ decomposition of H₂O₂ produces O₂ bubbles to realize the chemical drive of the micromotor with a speed of 128.33 ± 5.012 μm s⁻¹ (5% H₂O₂). Due to the high peroxidase activity and voluntary movement of MgAl-LDH/MFZ@HRP, catechol could be detected sensitively with a detection limit of 6.92 × 10⁻⁷ M. Moreover, catechol could be rapidly degraded by hydroxyl radical (˙OH) and superoxide anion (O₂˙⁻) produced by Fenton reaction, and the degradation rate could reach 96%. This study provides a promising multifunctional micromotor for simultaneous determination and removal of organic pollutants from wastewater.