ZnS纳米材料的光致发光和光催化性能

Photoluminescence and photocatalytic properties of ZnS nanometer materials

利用水热法制备ZnS纳米材料,通过X射线衍射（XRD）、扫描电子显微镜术（SEM）、光致发光（PL）对ZnS的结构及其物理性质进行研究,同时探讨退火对样品性能的影响.通过光谱分析发现,在400~650 nm附近有525 nm左右的绿光发射峰,该峰峰强随ZnS前驱体溶液中n（Zn（CH3COO）2）/n（（NH2）2CS）的增加而明显减弱,从不同比例样品的对比可以得出525 nm处的绿光发射峰是由ZnS纳米结构中的锌空位而引起.制备的ZnS纳米颗粒有良好的光催化效果.对样品进行高温退火处理,发现样品退火后结晶度升高,PL绿光发射峰峰强明显降低,催化性能也从50%上升到70%,说明高温退火能有效修复ZnS纳米颗粒在制备过程中由于浓度不均而引起的锌空位.

ZnS nanostructures synthesized through solvothermal process are studied by XRD,SEM,PL.The annealing effects on the ZnS samples are discussed.The photoluminescence（PL） band centered at about 525 nm has been observed under excitation in the range of 400～650 nm.The PL intensity reduces greatly with the increase of the ratio of zinc and sulfur sources in the preparation process.Spectral examinations and analyses reveal that the 525 nm emission peak indeed originates from the electronic states caused by the zinc vacancies.The photocatalysis results show that ZnS sample has a good photocatalytic activity.The green emission peak intensively decreases with the enhancement of crystallinity for the post annealing,and the photocatalytic performance is also increased from 50% to 70%.It proves that high temperature annealing can effectively repair zinc vacancies due to the uneven concentration in the preparation of ZnS nanostructures.