Solvothermal Synthesis Of Sulfide Nano-and Microcrystalline Materials And Its Mechanism

In this dissertation, hydrothermal and solvothermal technique for the synthesis of inorganic materials were developed. we report a solvothermal route to synthesize Bi₂S₃ nanowires adopting an inorganic-surfactant (BiCl₄^--CTA⁺) lamellar structure as precursors and water, ethanol as solvents respectively. CdS nanocrystals were synthesized in hydrothermal systems and then were recrystallized to obtain CdS hexagon tubular microcrystals. The ZnS hollow microspheres composed by many small ZnS nanoparticles were synthesized successfully in hydrothermal-ethanol systems and the gas SO₂ produced in our reaction process acted as a soft template. The good disperse MnFe₂O₄ nanocrystals were synthesized successfully in hydrothermal-glycol systems adopting MnO(OH) nanowires as precursors by a modifying co-precipitation method. The main points can be summarized as follows:1. The surfactants are introduced into the solvothermal technique. It was reported that the BiCl₄^- could react with CTA⁺ to form BiCl₄^--CTA⁺ lamellar structure. we adopted the lamellar BiCl₄^--CTA⁺ as a precursor for formation the lamellar Bi₂S₃ firstly. Moreover, much evidence demonstrates that lamellar structures, regardless of whether they are natural or artificial, have a strong tendency to form wires or tubes. With the increase of the reaction time, the lamellar Bi₂S₃ begin to roll onto them and formed nanowires bundles. And finally the naowires bundles were separated to form uniform single nanowires. This reliable method can be controlled and is expected to be applicable to the preparation of 1D nanostructures of other inorganic compounds, such as the Sb₂S₃ nanowires in our experiment.2. Hydrothermal preparative technique was developed. CdS nanocrystals were firstly synthesized, and then recrystallizing the nanocrystals by controlling the temperarure, mineralizer concentration and the fill factor grew the hexagon...