The a-ZnO NBs can be confirmed as an amorphous structure; the a-ZnO NBs will become new growth areas to keep extending the length of the a-ZnO NBs or growing extra a-ZnO NBs, as illustrated

in Figure 3a, and there are amorphous layers around the c-ZnO NW near the roots of Thiazovivin research buy a-ZnO NBs, as shown in Figure 3b. The c-ZnO NW exhibit good crystalline feature with the growth along [001] direction, as shown in Figure 3c. The surface caves can be found on the c-ZnO NWs surface, and those caves might be the humidity influence; the dissolution direction is along [010], as shown in Figure 3d. Figure 3 The spontaneous growth of a-ZnO NBs. (a) The a-ZnO NBs became new growth areas; amorphous nanostructures are around the a-ZnO NBs. (b) There are also amorphous layers on the c-ZnO NW near the roots of a-ZnO NBs. (c) ZnO NWs exhibit a single crystalline feature with the growth along [001] direction. (d) There are surface caves can be found on the c-ZnO NW due to the humidity influence; the dissolution direction is along [010]. For general condition, the spontaneous reaction is loath to reveal in the ZnO NWs application; therefore, we have suppressed the spontaneous reaction from our c-ZnO NWs devices by using surface oxygen/hydrogen plasma treatment [30]. Due to dangling bonds on the surface of c-ZnO NWs, H2O molecules would be absorbed on the c-ZnO NWs surface much easier. If we can prevent the H2O molecule from the surface of the

c-ZnO NWs, the spontaneous reaction might not happen AZD1152 mw and the ZnO nanodevices would maintain the functionality and performance. The c-ZnO NWs surface passivation can slow down the interaction between the moisture solution and c-ZnO NWs surface; the passive c-ZnO NWs would not have the spontaneous reaction in the same humidity treatment, as seen in Figure 4a,b,c,d).

Using oxygen/hydrogen plasma (60 mW) to occupy the oxygen vacancy, the a-ZnO NBs spontaneous reaction can be suppressed, compared with the unpassive c-ZnO NWs. Both O2 and H2 plasma can improve the UV detection Urocanase ability, but the H2 plasma treatment has stronger enhancement, compared with O2 plasma treatment, as shown in Figure 4e,f. The UV sensing ability of ZnO NWs device also can be enhanced more than twofold by H2 plasma treatment, as shown in Figure 4f. The plasma treatment not only can suppress the spontaneous reaction but also can enhance the UV sensing ability of the ZnO NWs devices. Figure 4 The c-ZnO NWs have been Rapamycin mouse passivated by O 2 /H 2 plasma treatment. (a, b) c-ZnO NW with O2 plasma (60 mW, 1 min) passivation has maintained the original forms after 48 h humidity (80% ± 2.5%) treatment. (c, d) ZnO NWs with H2 plasma (60 mW, 1 min) passivation also have no a-ZnO NBs spontaneous reaction from the ZnO NWs. (e) For O2 plasma treatment, the UV sensing ability can be improved. (f) For H2 plasma treatment, the UV sensing ability of ZnO nanodevice also enhanced more than two fold.