Single crystalline Sr germanate nanowires and their photocatalytic performance for the degradation of methyl blue

Abstract

Single crystalline Sr germanate nanowires have been synthesized by a facile hydrothermal process without any surfactants at a low temperature. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) diffusion reflectance spectra have been used to characterize the structure, morphology, size and optical properties of the Sr germanate nanowires. The nanowires with the orthorhombic SrGeO₃ phase have the diameter of 50 to 200 nm. The morphology and size of the Sr germanate nanowires can be controlled by adjusting the hydrothermal temperature, reaction time and surfactant species. The photocatalytic activity of the Sr germanate nanowires has been evaluated by the degradation of methylene blue (MB) under UV-vis light irradiation. The roles of the irradiation time, the content of the Sr germanate nanowires and the MB concentration on the MB degradation have been investigated. The Sr germanate nanowires present a degradation ratio of 83.22% after irradiation for 4 h over 10 mg Sr germanate nanowires in a 10 ml 10 mg L⁻¹ MB solution.