Experiment: Synthesis of BiOI microspheres:0.728 g Bi(NO 3 ) 3 •5H 2 O in 20 mL absolute ethanol in 100 mL flask and 0.249 g KI in 40 mL distilled water were prepared first. After completion of dissolution, KI solution was added drop-wise into the Bi(NO 3 ) 3 •5H 2 O solution with stir. Adjust the pH of the mixture to 7 by adding 1.5 M NH3•H2O, then, put the mixture in oil bath maintained at 80 for 3 h. The precipitates were collected by centrifugation, washed several times with distilled water and ethanol and finally dried in an oven overnight at 60 C. Finally, BiOI microspheres (diameter: 2~4 µm) were obtained. Characterization of BiOI microspheres:The scanning electron microscopy (SEM) images ( Figure S1A to Bi-O bond while the peak at 532.1 eV can be attributed to the hydroxyl groups on the surface of sample. The XPS spectrum of I 3d is shown in Figure 2C(d).The peaks with binding energy

A novel light-driven Au-WO@C Janus micromotor based on colloidal carbon WO nanoparticle composite spheres (WO@C) prepared by one-step hydrothermal treatment is described. The Janus micromotors can move in aqueous media at a speed of 16 μm/s under 40 mW/cm UV light due to diffusiophoretic effects. The propulsion of such Au-WO@C Janus micromotors (diameter ∼ 1.0 μm) can be generated by UV light in pure water without any external chemical fuels and readily modulated by light intensity. After depositing a paramagnetic Ni layer between the Au layer and WO, the motion direction of the micromotor can be precisely controlled by an external magnetic field. Such magnetic micromotors not only facilitate recycling of motors but also promise more possibility of practical applications in the future. Moreover, the Au-WO@C Janus micromotors show high sensitivity toward extremely low concentrations of sodium-2,6-dichloroindophenol (DCIP) and Rhodamine B (RhB). The moving speed of motors can be significantly accelerated to 26 and 29 μm/s in 5 × 10 wt % DCIP and 5 × 10 wt % RhB aqueous solutions, respectively, due to the enhanced diffusiophoretic effect, which results from the rapid photocatalytic degradation of DCIP and RhB by WO. This photocatalytic acceleration of the Au-WO@C Janus micromotors confirms the self-diffusiophoretic mechanism and opens an opportunity to tune the motility of the motors. This work also offers the light-driven micromotors a considerable potential for detection and rapid photodegradation of dye pollutants in water.

Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven TiO2–Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue (10−5 g L−1), cresol red (10−4 g L−1), and methyl orange (10−4 g L−1), respectively. We determined that the micromotor speed changes depending on the type of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and TiO2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation. In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and “on-the-fly” degradation of dye pollutants in aqueous environments. Electronic supplementary materialThe online version of this article (doi:10.1007/s40820-017-0133-9) contains supplementary material, which is available to authorized users.

At present, numerous methods have been developed to prolong the durability of superamphiphobic coatings. These studies mainly focus on the repairing of coating surface morphology and the supplement of low surface energy materials. These self-healing methods are performed on the surface of the coatings, which will not be self-healed when deep damage occurs. To provide a viable strategy to self-heal deep damaged coatings such as tearing and sharp cutting, a series of UV light curable self-healing superamphiphobic coatings were fabricated by deposition of hydrophobically modified and functionalized Al2O3 nanoparticles (SMANP) on the surface of UV light curable polyurethane acrylic resin containing disulfide bond (DSPUA) and subsequent UV light irradiation. The resultant coating can repel both water and oil and performs excellent superamphiphobicity. With the help of the disulfide exchange reaction, the coatings perform excellent self-healing behavior after sharp cutting; the scratches gradually disappear, and the surface recovers to an integrated one. Meanwhile, the coatings can also restore their superamphiphobicity after heating or UV irradiation. Moreover, the effects of temperature, disulfide bond contents, and UV light irradiation on the self-healing performance of coatings were studied in detail. It has been demonstrated that increasing temperature or disulfide bond content can improve the self-healing performance of coatings; meanwhile, UV light irradiation can dramatically improve the self-healing rate. The current findings not only unlock more possibilities of fabricating self-healing superamphiphobic coating but also provide preliminary understanding of the self-healing kinetics based on disulfide exchange reaction.

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