EFFECTS OF PREPARATION PARAMETERS ON ONE-DIMENSIONAL CdS NANOSTRUCTURES BY DIPHENYLTHIOCARBAZONE-ASSISTED SOLVOTHERMAL METHOD

One-dimensional (1D) single crystalline CdS nanostructures have been successfully synthesized via a diphenylthiocarbazone-assisted solvothermal route. The results revealed that the microstructure and optical absorption properties of 1D CdS nanostructures were temperature and time dependent owing to thermodynamically and kinetically controlled growth. Single crystalline CdS nanowires with a diameter of 80 nm and length of 20 mu m were synthesized at 180 degrees C for 96 h. At moderate temperature (180 degrees C), the morphology of the products transformed from irregular short rods to uniform long rods as the reaction time prolonging in a kinetically controlled growth regime. Only nanorods were obtained at a temperature as low as 120 degrees C even extending reaction time to 260 h due to thermodynamic limited growth. At high temperature (250 degrees C in this system), the products were nanowires with larger diameter but lower aspect ratio since the growth rates on both lateral and axial directions were accelerated. Moreover, the optical absorption spectra revealed that the CdS nanowires showed a blue shift compared with bulk CdS. Two optical absorption peaks appeared due to the nanometer effect in the radial and lengthwise directions of CdS nanowires. The growth mechanism of 1D CdS nanostructures was discussed.