The nanosheets attached to the facetted nanowires could easily be detached from the substrate and dispersed into an aqueous solution via sonication for several seconds, which enabled us to easily prepare TEM samples. Figure 3 Time-dependent buy AG-881 growth morphology of Ag nanosheets. Cross-sectional SEM images of Ag nanosheets with deposition times of (a) 20, (b) 40, (c) 70, and (d) 120 min. (e) Enlarged top-view SEM image of the specimen shown in (c). (f) Schematic diagram of illustrating the growth of hexagonal nanosheets. (The insets denote the top-view SEM images.). As shown in Figure 4, the thickness of the nanosheet depended
on the thickness of the facetted nanowires that grew over the islands nucleated on the substrate. Therefore, the thickness of Ag nanosheets could be controlled by varying the island size. In the previous work, the island size EPZ015666 was controlled by the deposition
frequency and reduction/oxidation potentials of the reverse-pulse potentiodynamic mode . When the deposition frequency was varied in the range of 1 to 1,000 Hz under the same deposition parameters (V O, V R, and duty) for the sample shown in Figure 1, the thickness and size of Ag nanosheets were controlled in the range of 20 to 50 nm and 3 to 10 μm in size, respectively (Figure 4). At the low frequency of 1 Hz, the deposit was composed of irregular Ag nanosheets shown in Figure 4a. With increase of the frequency from 10 to 1,000 Hz, the planar Ag grew and the thickness decreased from 50 to 20 nm, approximately. Also, the nanosheet selleck chemical size increased with the frequency increasing, as shown in Figure 4. It is noted that the facetted nanowires became thinner with the frequency increasing in the range. It is presumed that the nucleation size became smaller with the shorter period of reduction process. Vildagliptin We investigated the effects of the reduction/oxidation potentials on
the growth of Ag nanosheets, as shown in Figure 5. At the reduction potential of −10 V (Figure 5a), the deposit grew so slowly comparing to that shown in Figure 1. It seems that the reduction potential should be applied over V R = −10 V. At the higher reduction potential of −20 V, a lot of nanosheets were deposited and extra nanoparticles grew on the nanosheet surface, as shown in Figure 5b. This was due to the fact that the higher reduction potential leads to higher nucleation and growth rates in electrochemistry. Also, when the oxidation potential was decreased to 0.05 V comparing with the samples (V O = 0.2 V) shown in Figure 1, nanosheets of several micrometers in size grew, and small nanoparticles were deposited on the surface of the nanosheets, as shown in Figure 5c. At the higher VO of 0.4 V, nanosheets grew without nanoparticles on their surface, but the amount of nanosheets decreased much, as shown in Figure 5d.