Micromotor-assisted bifunctional platform for efficient detection and removal of aniline

Studies on combining the catalytic activity of nanomaterials with self-propelled micro/nanomotors for determining and degrading contaminants in the water environment are rapidly growing, especially in constructing cost-effective platforms that can simultaneously achieve both functions. Herein, we report a novel bifunctional magnetic micromotor (CA-MnO2@Co–N/C) with greatly enhanced micromixing performance, as well as improved detection and degradation capabilities for aniline in water. The CA-MnO2@Co–N/C micromotors were composed of a bioderived carbon matrix, ZIF-67-derived magnetic Co–N/C, and MnO2 nanosheets. The micromotors not only exhibited excellent peroxidase-like activity (POD-like activity) but also showed superior Fenton-like catalytic activity. The micromotors achieved self-propulsion motion by generating O2 bubbles from the catalytic decomposition of H2O2, with the highest speed of 398.88 μm s−1 in 7 wt% H2O2. The CA-MnO2@Co–N/C micromotors exhibited sensitive detection and efficient removal toward aniline in water, which was attributed to the synergistic effect between hierarchical structure, citric acid modification and bubble-driven propulsion. The limit of detection (LOD) for aniline was 0.185 μM, and the highest removal efficiency of aniline reached 83% in 180 min based on our dynamic catalytic reaction platform. In comparison to traditional micro/nanomaterials, the simple fabrication process, self-propulsion performance, and excellent catalytic activity of CA-MnO2@Co–N/C micromotors provided a promising strategy for a dynamic environmental monitoring and remediation platform.