微波水热法制备CdS单分散纳米球及其形貌控制

采用微波水热法,以醋酸镉(Cd(CH3COO)2.2H2O)为镉源,硫脲(CS(NH2)2)为硫源,制备出了具有单分散球形形貌的CdS纳米晶。应用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、能量色散谱仪(EDS)、高分辨透射电子显微镜(HR-TEM)、紫外可见吸收光谱(UV-Vis)等测试手段对样品的物相、形貌、元素组分及吸光性能进行了表征,并以罗丹明B溶液的降解脱色反应来考察了其的光催化活性。结果表明:随着S/Cd物质的量比(nS/nCd)逐渐增大,产物会出现由刺球链状向分散球形过渡的规律性变化。在一定的nS/nCd比的条件下可以合成出大小均匀、分散性较好的六方相CdS纳米球。样品对可见光有较强吸收,存在着一定的红移现象。在可见光照射下,硫化镉单分散纳米球具有更高的光催化活性。

Preparation and Morphology Controlling of Monodisperse CdS Nanospheres by Microwave Hydrothermal Process

Monodisperse CdS nanospheres were successfully prepared by microwave hydrothermal process using cadmium acetate Cd(CH₃COO)₂·2H₂O] and thiourea CS(NH₂)₂] as the source material. The phase composition, morphologies and elemental constitution of the product were characterized by X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), electron energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM). Ultraviolet-visible (UV-Vis) was used to investigate the optical property of the CdS nanocrystallines whereas catalytic activity was evaluated by the photocatalytic degradation to rhodamine B (RB) reaction. The results indicated that the morphology of prepared CdS transforms regularly from acanthosphere-like chain-shaped structure to monodisperse sphere with the increase of S/Cd molar ratio. Hexagonal CdS nanospheres with good uniformity and dispersibility can be prepared at certain n_S/n_Cd molar range. The samples had a relatively strong absorption at visible region with a obvious red shift comparing to the common bulky CdS particles. The monodisperse CdS nanospheres had higher catalytic activity under visible light irradiation.