Large-scale synthesis and growth conditions dependence on the formation of CuGeO 3 nanowires

Abstract

CuGeO 3 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 GeO 2 and Cu(CH 3COO) 2·H 2O 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, GeO 2 concentration, copper source materials, surfactants and solvents on the formation, morphologies and sizes of CuGeO 3 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 CuGeO 3 nanostructures. The nucleation and crystalline growth mechanism are proposed to explain the formation and growth of CuGeO 3 nanowires. The photoluminescence spectrum of the CuGeO 3 nanowires exhibits three fluorescence emission peaks centered at 421 nm, 488 nm and 529 nm as the excitation wavelength is 235 nm.