pH值对微波水热法制备γ-MnS微晶形貌及光学性能的影响

Influences of pH Values on Morphology and Optical Performance of γ-MnS Microcrystalline Prepared by Microwave Hydrothermal Method

采用微波水热法,分别以氯化锰和硫代乙酰胺为锰源和硫源,在不同的pH条件下合成了γ-MnS微晶。利用X射线衍射仪(XRD),扫描电子显微镜(SEM),场发射扫描电子显微镜(FESEM),透射电子显微镜(TEM)对样品的物相组成和微观形貌,粒径大小进行了表征。结果表明:在pH大于6时均能合成出结晶性较好的纤锌矿结构γ-MnS,随着pH的增大,产量提高,产物的粒径逐渐变小且自组装为球状微晶,粒径为0.5μm,利用紫外-可见吸收光谱分析(UV),自组装γ-MnS微晶球在300～400 nm处出现了较强的吸收峰,其光学带隙随着pH的增大而减小,在光电领域具有潜在的应用。

The γ-MnS microcrystalline was synthesized at different pH values by microwave hydrothermal（M-H） method using manganese chloride and thioacetamide as raw materials.The phase composition,micro-structure,grain size of the products were characterized by XRD,SEM,FESEM,TEM.The results show that good crystalline wurtzite structure γ-MnS could be synthesized when pH6.As the pH value increasing,production of the microcrystalline γ-MnS increased,the particle size of the products became smaller and self-assembled into spherical crystallites with the particle size of 0.5 μm.UV-Visible spectra analysis shows that self-assembled spherical γ-MnS microcrystalline have a strong absorption in the ultraviolet spectrum between 300 nm and 400 nm.The optical band gap of the γ-MnS spherical microcrystals decreases as the pH values increasing which could have potential applications in photoelectric areas.