Systhesis And Characterization Of Bi₂S₃ Nanostructures Under Ultrasonic Radiation

In this thesis,we mainly discussed the synthesis of Bi₂S₃ nanostructures under ultrasonic radiation.By means of changing the reaction conditions,Bi₂S₃ nanostructures were obtained.Powder x-ray diffraction(XRD),transmission electron microscopy(TEM) and scanning electron microscopy(SEM) were employed to characterize the Bi₂S₃ nanostructures.The major researches might be summarized as follows:1.Bismuth nitrate and thiourea were used as bismuth source and sulfur source, respectively,as well as glycol and dilute nitric acid as solvents.Bismuth nitrate was dissolved into glycol as the oil phase,and thiourea was dissolved into the dilute nitric acid as the water phase.2.Changing the proportion of glycol in the system,from 0 to 100%,tOhe different morphologies of Bi₂S₃ nanostructures were obtained.We found that the best proportion of glycol in the system is 50%or near the 50%.3.The influence to the formation and morphology of the Bi₂S₃ nanostructures caused by the concentration of dilute nitric acid was also studied.Keeping the total volume unchanged,we change the proportion of water and dilute nitric acid to be 1:3, 1:1,3:1 in the system,respectively.4.The influence of the parameters of ultrasonic radiation was investigated. While fixing the interval time as 2 min,four ultrasonic parameters were employed, including 2 min per time/5 cycles;1 min per time/5 cycles;5 min per time/5 cycles; 2 min per time/3 cycles.In conclusion,our results show that when the proportion of glycol in the system is 50%,the proportion of water and dilute nitric acid is 1:1 in water phase,the reaction time is 16h,the ultrasonic parameters is 2 min per time/5 cycles.The near monodisperse Bi₂S₃ flowerlike nanostructures were obtained.