Chemical Conversion Reaction between CdS Nanobelts and ZnS Nanobelts by Vapor Transport

Single-crystalline wurtzite CdS nanobelts are completely converted into single-crystalline wurtzite ZnS nanobelts by Zn vapor transport (at 800 °C). In contrast, the ZnS nanobelts are not completely transformed into CdS nanobelts by Cd vapor transport but yield Cd-doped (up to 60%) ZnS nanobelts (at 1000 °C). This result indicates that the conversion reaction of the CdS nanobelts into the ZnS nanobelts takes place more efficiently, as compared to the opposite reaction. At temperatures lower than the conversion temperature, a CdS−ZnO nanobelt−nanowire hybrid structure grew, in which the ZnO nanowires were aligned in the [0001] direction of the CdS nanobelts. We suggest that the conversion reaction of the wurtzite CdS structure proceeds preferentially through their polar (001) planes.