In that time, the Zn2+ ions are diffused into the seed layer by the Coulombic this website attraction under strong electric field and then combined with OH− ions. Finally, the ZnO NRAs are formed and self-assembled with a preferred growth directionality of c-axis in wurtzite crystal structure. Figure 1 Schematic diagram. ED process for the ZnO NRAs on CT substrates. (a) The preparation of CT substrate, (b) the ZnO seed-coated CT substrate, and (c) the integrated ZnO NRAs on the seed-coated CT substrate. Figure 2 shows
the SEM images of the integrated ZnO NRAs on the seed-coated CT substrate at an external cathodic voltage of −2 V for 1 h under ultrasonic agitation. The insets of Figure 2c show the magnified SEM image of the selected region and the photographs of the bare CT and the ZnO NRAs-integrated XAV-939 manufacturer CT substrate. In the perspective view of the sample in Figure 2a, the shape of the textile was kept intact. With a closer view, as shown in Figure 2b, the ZnO NRAs were densely and clearly coated over the overall surface of Ni/PET fibers with few ZnO microrods. During the ED process, indeed, the ZnO was formed not only at the surface of seed layer, but also in the growth solution because some Zn2+ ions react with the remaining OH− ions
supported from hexamethylenetetramine. Therefore, some zinc hydroxides were created and grown into the microrods in growth solution, which were attached at the already organized ZnO NRAs on the seed layer. For this reason, the ultrasonic agitation was employed to avoid such attachments. As shown in Figure 2c, it can be clearly observed that
the ZnO nanorods were aligned with varying vertical angle and integrated with the regular-sized ones. The sizes/heights of ZnO nanorods were approximately estimated to be about 65 to 80 nm/600 to 800 nm. From the selleck inhibitor photographs, the ZnO NRAs were clearly deposited on the seed-coated CT substrate. Additionally, the ZnO NRAs-integrated CT substrate became much darker compared to the bare CT substrate due to the antireflection effect, because the ZnO NRAs provide a graded effective refractive index profile between air and the CT substrate [25, 26]. Therefore, the CT substrate can absorb more light from air via the ZnO NRAs due to the reduced surface reflection, thus leading to a black-colored surface like black silicon [27]. Figure 2 FE-SEM micrographs. Integrated ZnO NRAs on the seed-coated CT substrate at an external cathodic voltage of −2 V for 1 h under ultrasonic agitation. (a) Low magnification, (b) medium magnification, and (c) high magnification. The insets of (c) show the magnified FE-SEM image of the selected region and the photographs of the bare CT and the ZnO NRAs integrated CT substrate. To investigate the effects of seed layer and ultrasonic agitation on the growth property, the ZnO NRAs were synthesized on bare CT substrate in ultrasonic bath (i.e.