NIR-light propelled bowl-like mesoporous polydopamine@UiO-66 metal−organic framework nanomotors for enhanced removal of organic contaminant

Chemical-propelled micro/nanomotors exhibit promising applications in contaminant removal. However, additional hydrogen peroxide (H2O2) often needs to be added to provide chemical propulsion power. Herein, we designed and fabricated a near-infrared (NIR)-light propelled bowl-like nanomotor by the heterogeneous growth of UiO-66 metal−organic framework (MOF) on mesoporous polydopamine (PDA), in order to achieve the enhanced removal of organic contaminant without further addition of any fuel such as H2O2. Under light irradiation, the asymmetric nanobowl structure of PDA with high photothermal conversion efficiency can produce an asymmetric thermal gradient field, resulting in self-thermophoretic propulsion. Noteworthily, the motion speed of [email protected] nanomotors can reach 18.8 μm/s at the power density of 3 W/cm2 under 980 nm NIR light irradiation. The [email protected] nanomotors show excellent adsorption efficiency of over 78% for methylene blue (MB), and it has a maximum adsorption capacity of 134 mg/g for MB within 40 min under NIR light irradiation. The NIR-light propulsion nanomotors may have potentials in the removal of organic contaminant from the wastewater.