Molecular-Level Design of Polymeric Semiconductor Nanomotors with Multichannel Sensitive 3D Motion for Microorganism Inactivation.

The advancement of high-performance photocatalysts is crucial for the iteration of light-driven micro/nanomotors. However, most existing light-driven micro/nanomotors, which are typically fabricated from inorganic semiconductors, suffer from limited visible-light absorption and inadequate control over 3D motion. Polymeric semiconductors, as emerging photocatalytic materials, feature narrow bandgaps, tunable band structures, and the potential for rational molecular design to optimize activity. This study introduces phenolic resins as efficient semiconductor photocatalysts, establishing a novel platform for constructing light-driven nanomotors. Among them, the m-aminophenol-formaldehyde resin nanomotor, synthesized via hydrothermal methods, exhibits exceptional mobility due to its efficient photoelectric conversion and charge transfer behavior. Its outstanding photoelectrochemical properties originate from a benzoxazine-quinoid structure with a low HOMO-LUMO gap (1.90 eV). These nanomotors feature broad-spectrum light absorption and can respond to various external stimuli, including light intensity, wavelength, and H2O2 concentration, enabling precise control over in-plane and vertical motion with adjustable speed and directionality. As a proof of concept, the nanomotors demonstrate superior photodynamic inactivation of Karenia mikimotoi under visible light exposure, surpassing TiO2 nanoparticles in antimicrobial efficiency. This work explores the relationship between molecular structure, photocatalytic performance, and motion behavior, providing instructive insights for designing light-driven nanomotors with advanced motion manipulation.