Owing to the deoxidized
plentiful crystal nuclei, the higher ion concentration facilitated the form of a two-dimensional thin film at a lower potential in the electrolyte. When the ion concentration was lower, the amount of deoxidized crystal nuclei did not afford the needs of thin film growth, and the two-dimensional growth form would be replaced by the one-dimensional growth form. The schematic diagrams of the experimental setup were shown in Figure 1b. Figure 1 Scanning electron microscopy image of the PbTe/Pb nanostructure. (a) The representative SEM image of PbTe/Pb nanostructure arrays with a field of view of 30 μm (w) × 20 μm (h). (b) The SEM image of the single PbTe/Pb nanostructure. The upper right insert figure gives the central configuration schematic of the electrochemical selleckchem cell. The lower left insert figure gives the applied voltage waveform. The applied voltage varies from 0.5 to 0.9 V in a square waveform with SC75741 research buy 1 Hz frequency. The electrodeposition of the PbTe/Pb nanostructure arrays was carried out by applying a square wave potential with a
frequency of 1 Hz (in Figure 1b) across the ultrathin layer. The electrolyte was prepared using analytical reagent Pb(NO3)2, TeO2 (Fluka, Sigma-Aldrich Corporation, St. Louis, MO, USA), and Millipore water (Millipore Co., Billerica, MA, USA). The ion concentrations of Pb2+ and HTeO2
+ in the electrolyte were 0.005 and 0.001 M, respectively. The pH value of the electrolyte was Emricasan mw adjusted to 1.87 by nitric acid. The treated silicon substrate (20 × 20 mm2) (Fluka) was first placed on the Peltier element. Silicon was treated using chemical erosion and oxidation process, which would bring an insulation and uniform thickness of the SiO2 layer on the surface of the silicon wafer. Next, the two parallel lead foil electrodes with 30-μm thickness (Fluka) were placed on the substrate and filled with the electrolyte. A cover glass was put on the electrodes, and the simple electrolytic cell was assembled. After that, the temperature Florfenicol control system consisted of a circulating water bath, and the Peltier element was used to solidify the electrolyte. Due to the partitioning effect, the solute in the electrolyte could be partially expelled from the solid in the solidification process. The concentrated electrolyte layer with 300-nm thickness was formed between the ice from the electrolyte and the SiO2/Si substrate when the temperature dropped to −5.20°C. The temperature played an important role to the control of the electrolyte layer thickness and concentration. The lower temperature could cause the solute in the electrolyte layer to be further expelled from the solid, which made the concentration of the electrolyte layer more concentrated.