Qian-Feng Zhang

Low temperature growth and characterizations of single crystalline CuGeO3nanowires

Single crystalline CuGeO3nanowires with a diameter of 30–200 nm and a length of >10 µm have been prepared by a facile hydrothermal deposition route at low temperature. The nanowires are orthorhombic single crystals, which are supported by X-ray diffraction, selected area electron diffraction, high-resolution transmission electron microscopy and Raman analyses. Room temperature photoluminescence (PL) measurement shows a strong blue light emission peak at 442 nm with a broad emission band. The formation and growth of CuGeO3nanowires are proposed based on the oxide-assisted growth mechanism. The CuGeO3nanowires with single crystalline nature appear to be one of the best candidates for investigation of the related physical, chemical properties and further potential applications among ternary nanometallic oxides.

Synthesis and characterizations of calcium germanate nanowires

Crystalline calcium germanate nanowires with a diameter of 50–200 nm and length of several dozens of micrometres have been synthesized by a simple and facile hydrothermal process. X-ray diffraction and high-resolution transmission electron microscopy results show that the crystalline calcium germanate nanowires are mainly composed of tetragonal Ca2GeO4, orthorhombic Ca2Ge7O16 and triclinic CaGe2O5 phases. The role of different growth conditions demonstrates that the hydrothemral temperature, reaction time, compactness, Ca source materials and surfactants play an essential role in the formation and size of the calcium germanate nanowires. The nucleation and crystalline growth mechanism are proposed to explain the formation and growth of the calcium germanate nanowires. The photoluminescence spectrum of the calcium germanate nanowires shows three fluorescence emission peaks centered at 421 nm, 488 nm and 529 nm, exhibiting a promising potential for optical applications.

Growth of calcium vanadate nanorods

Calcium vanadate nanorods with sheaf-shaped structures have been synthesized by a facile hydrothermal route using calcium acetate and sodium orthovanadate as the raw materials. The as-prepared calcium vanadate nanorods are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and infrared and photoluminescence (PL) spectroscopy. Calcium vanadate nanorods exhibit single crystalline structure and XRD confirms the crystal structure to be hexagonal Ca10V6O25 phase. The average diameter and length of the calcium vanadate nanorods are about 50 nm and 3 μm, respectively. A possible formation process of the nanorods has been elucidated.