Dual-propelled PDA@MnO2 nanomotors with NIR light and H2O2 for effective removal of heavy metal and organic dye

Abstract

Self-propelled micro/nanomotors hold significant potential to achieve innovative pollutant removal application. Most current micro/nanomotors are designed for single modal propulsion and a specific type of contaminant, resulting in limited applications in complicated water environments. Herein, we develop a dual-propelled asymmetric bowl-like structured polydopamine (PDA)@MnO2 nanomotor, which possesses the capacity of both near-infrared (NIR) light and hydrogen peroxide (H2O2) propulsion. The PDA@MnO2 nanomotors were synthesized by introducing many thin MnO2 nanosheets onto the surface of bowl-like mesoporous PDA nanoparticles via in-situ oxidative growth method. The obtained PDA@MnO2 nanomotor shows effective diffusion coefficient of 25.0 µm2/s under NIR light irradiation (808 nm, 3 W/cm2). Under the NIR light irradiation, the PDA@MnO2 nanomotor displays the enhanced removal efficiency of Pb2+ and methylene blue (MB), with the adsorption capacity of 176 mg/g for Pb2+ and 81 mg/g for MB. Our developed dual-propelled PDA@MnO2 nanomotor may have a promising potential for removal application of multiple pollutants.