Light-driven synthetic micro/nanomotors have attracted considerable attention in the recent years due to their potential applications and unique performances such as remote motion control and adjustable velocity.In this work,we demonstrate a new concept of the dye-enhanced self-electrophoretic propulsion of light driven TiO2-Au Janus micromotors in dye aqueous solutions.The speeds of micromotors in 10-5 g L-1 Methyl Blue(MB),10-4 g L-1 Cresol Red(CR)and 10-4 g L-1 Methyl Orange(MO)aqueous solutions respectively increase by 1.7,1.5 and 1.4 times compared with the speed of micromotors in water.The speed of micromotors strongly depends on the type of dyes because of their different photodegradation rates.After depositing a paramagnetic Ni layer between Au layer and Ti O2,the micromotor can be precisely navigated under an external magnetic field.Such magnetic micromotors not only facilitate recycling of micromotors but also offer micromotors an excellent reusability in the degradation and detection of dyes.In general,such photocatalystic micro/nanomotors promise a considerable potential for rapid detection and “on-the-fly” degradation of dye pollutants in water.Utilizing harmless and renewable visible light to supply energy for micro/nanomotors in water represents a great challenge.In view of the outstanding photocatalytic performance of bismuth oxyiodide(BiOI),visible light driven BiOI-based Janus micromotors have been developed,which can be activated by a broad spectrum light including blue and green light.Such BiOI-based Janus micromotors can be propelled by photocatalytic reactions in pure water under environmentally friendly visible light without the addition of any other chemical fuels.The remote control of photocatalytic propulsion by modulating the power of visible light is characterized by a mean-square displacement(MSD)analysis of optical video recordings.In addition,the self-electrophoresis mechanism has been confirmed for such visible light driven BiOI-based Janus micromotors by demonstrating the effects of various coated layers(e.g.Al2O3,Pt and Au)on the velocity of motors.Furthermore,such visible light driven Janus micromotors exhibit light activated swarming behavior,which also can be modulated by different coated layers.The successful demonstration of the visible light driven Janus micromotors holds a great promise for future biomedical and environmental applications. |