| Zn Se, Ni Se2, Pb Se are three important semi-conducting opto-electronic materials, and have attracted much attention due to their unique physical, chemical properties and wide applications in opto-electronic devices and biological medicine,Also, they belong to the direct band series semi-conductor. Therefore we try to explore a special solvothermal method for the three kinds of nano-semiconductor compounds successfully in this paper, deeply studied its optical properties with great significance. The main contents in this paper contains as follows:Firstly, Zn Se crystal has been synthesized successfully by Salt-Alkali-Composited-Mediated method(SACM), which is that using molten mixed salt and alkali to replace traditional water or organic solvent as reacting environment for synthesizing nano-materials under relative low temperature. We studied the effect of reaction time and added deionized water on the morphology and the size of the products, meanwhile, the growth mechanism was proposed during reaction process.The result of the experiments shows that the deionized water was helpful for the growth of the nano-sheets, the size of the Zn Se nano-sheets can reach about 2um when the added deionized water was 6m L. The reaction time has also affect the morphology of the products, with a more uniform of morphology when the reaction time is 18 h. UV-visible absorption spectrum of the sheets exhibits the band gap of about 3.25 e V, therefore, we chose ultraviolet as the light source to carry out a series of photocatalytic degradation experiments and the result shows that the photocatalytic degradation properties of the Zn Se nano-sheets are good. And photocatalytic degradation efficiency of sample 3# can reach a maximum of 87.32%.Then, Ni Se2 and Ni0.85 Se nano-materials were also synthesized on the basis of the SACM method. The experiment results shows that the reaction time has a great influence on the products. The growth mechanism and the analysis of the process of product change was proposed. UV-visible absorption spectrum of the two kinds of products shows the band gap of 1.47 e V and 1.75 e V, which is not suitable for photocatalytic degradation experiment. And the electrochemical properties of Ni Se2 crystals are determined by cyclic voltammetry. The CV curve shows that the electrochemical properties of Ni Se2 crystals in alkaline solution is better than in neutral solution, and has good repeatability.So the products have good performance of repeated use.Pb Se nano-particles is a typical narrow band gap(Eg= 0.27 e V at 300 K) IV-VI semiconductor nano-crystalline material. Lastly, Pb Se nano-matreials were synthesized by two different methods: Composited-Molten-Salt method(CMS) and the SACM method. Field emission scanning electron microscope(SEM) and transmission electron microscope(TEM) images shows the products which were synthesized by different methods have different morphologies. The growth mechanism of Pb Se nano-materials was proposed and the reason of the formation of cubic Pb Se was also discussed. |
PDF Full Text Request