不同晶型纳米CdS的合成及其光催化活性

以醋酸镉为镉源，硫脲为硫源，采用配合物热分解法，通过改变硫脲/醋酸镉的摩尔配比，合成了具有不同晶型的纳米CdS．当n（S）／n（Cd）=0．5—3时，合成的CdS相分别为立方相（n（S）／n（Cd）=0．5），立方相和六方相的混相（n（S）／n（Cd）=1．0～1．5），六方相（n（S）／n（Cd）≥2）．通过XRD，TEM，UV—Vis光谱，IR光谱等对CdS的相组成，形貌，粒径，吸光性能，表面结构等进行了表征．光催化降解罗丹明B的活性结果表明，不同CdS相组成的活性顺序为立方相〉六方相〉混相（立方＋六方），其中立方CdS相由于有较强的吸附作用、光吸收性能和较小的粒径（10～13nm），对罗丹明B具有最好的光催化降解活性．

Synthesis and Photocatalytic Activity of Cadmium Sulfide with Different Crystal Structures

The cadmium sulfide(CdS) crystals were synthesized via a complex compound thermolysis method with different molar ratio of thiourea to acetate cadmium(S/Cd).The as-synthesized CdS samples are of cubic phase,mixed phase of cubic and hexagonal,and hexagonal phase while(n(S)/n(Cd)) are equal to 0.5,1.0~1.5,≥2,respectively.The phase composition,particle morphology and size,absorbance and surface structures of CdS were characterized by XRD,TEM,UV-Vis and IR spectra.The results of photocatalytic degradation to rhodamine B(RB) show that the activity orders of CdS concerning the phase compositions are cubic>hexagonal>cubic+hexagonal,where the cubic phase of CdS has the best photocatalytic degradation activity to RB because of its larger adsorption ability and absorbance and small particle size of about 10~13 nm.