Large-scale synthesis and growth conditions dependence on the formation of CuGeO3 nanowires

CuGeO3 nanowires in bulk with the diameter of 20–100 nm and length of several dozens of micrometers have been synthesized via a facile hydrothermal process using GeO2 and Cu(CH3COO)2·H2O as the raw materials in the absence of any surfactants. The synthesized nanowires are single crystals with an orthorhombic phase based on the X-ray diffraction, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy characterizations. The dependence of different growth conditions, such as reaction temperature, reaction time, compactness, GeO2 concentration, copper source materials, surfactants and solvents on the formation, morphologies and sizes of CuGeO3 nanostructures have been investigated. Proper selection and combination of the growth conditions are the key aspect to control the formation, morphology and size of the CuGeO3 nanostructures. The nucleation and crystalline growth mechanism are proposed to explain the formation and growth of CuGeO3 nanowires. The photoluminescence spectrum of the CuGeO3 nanowires exhibits three fluorescence emission peaks centered at 421 nm, 488 nm and 529 nm as the excitation wavelength is 235 nm.