Large-scale synthesis of ZnO nanowires using a low-temperature chemical route and their photoluminescence properties

Single-crystalline zinc oxide (ZnO) nanowires were synthesized from zinc powder and H2O through a simple chemical route at 730 degreesC in Ar atmosphere. The potential exists for bulk synthesis of ZnO nanowires at temperatures significantly less than the 200-300 degreesC of thermal evaporation methods reported formerly. Scanning electron microscopy and transmission electron microscopy observations reveal that the ZnO nanowires are structurally uniform, have lengths up to several hundreds of micrometers and diameters of about 40-60 nm and crystallize in a hexagonal structure. The growth of ZnO nanowires is controlled by the vapor-solid crystal-growth mechanism. Photoluminescence measurements show that the ZnO nanowires have a strong near-band ultraviolet emission at 380 nm and a green light emission at 520 nm caused by oxygen vacancies.