Visible light-driven multi-motion modes CNC/TiO2 nanomotors for highly efficient degradation of emerging contaminants

Abstract In this work, self-propelled multi-motion modes helix carbon nanocoil/TiO2(CNC/TiO2) nanomotors display efficient locomotion and offer effective “on-the-fly” removal of emerging contaminants in deionized water under visible irradiation are described. We are first to use the multi-motion modes (translation + rotating, stirring) photocatalytic nanomotors for the degradation of contaminants, which greatly enhance its mixing with pollutants in multiple dimensions, and it shows an excellent degradation efficiency of contaminants. The generation of multi-motion modes of nanomotor is mainly ascribe to its unique spiral structure. Except to the driving force (self-electrophoresis) induced by the asymmetric redox reactions, CNC/TiO2 nanomotors will also suffered from torque (T) and viscous drag (D) in the solution. Therefore, the different sizes CNC/TiO2 nanomotors may have different stress conditions, and resulting in different motion modes. The degradation effect of CNC/TiO2 nanomotors revealed that it can degrade more than 50% of phenol in 30 min. Such excellent degradation efficiency has not been reported in previous. It is novel that the coupling of high adsorption and capture capacity of helix CNCs and multiple mode motions of CNC/TiO2 photocatalytic nanomotors to achieve an efficient degradation for contaminants, which is expected to find a way to environmental remediation and security applications.