Facile hydrothermal preparation and characterizations of single crystalline Ge dioxide nanowires

Bulk-quantity single crystalline Ge dioxide nanowires (GeONWs) have been prepared via a facile and simple hydrothermal deposition process using GeO2 powder. Transmission electron microscopy (TEM) observations show that the GeONWs have a high purity, diameter ranging from 30 to 300 nm, and length of longer than 10 μm. X-ray diffraction, Fourier transform infrared, high-resolution TEM, and selected area electron diffraction pattern of the GeONWs indicate that the nanowires are single crystalline GeO2 with hexagonal structure. Room temperature photoluminescence measurement shows that the synthesized GeONWs have intense violet light emission and blue light emission at 370 and 476 nm, respectively. It is proposed that the GeONWs may follow the vapor-solid growth mechanism.