Abstract: In this work, the cubic/hexagonal cadmium sulfide (c/h⁃CdS) heterojunction catalyst was successfully prepared by solid phase reaction with cadmium acetate and thioacetamide as raw materials.The synthesized catalysts were characterized by means of XRD, SEM and SPV. The activity of photocatalytic degradation of rhodamine B (RhB) was evaluated by using visible light as the light source. The effect of calcination temperature on the photocatalytic performance of CdS was investigated, and the mechanism of the degradation process was discussed. The results suggest that with the increasing of calcination temperature, c⁃CdS is gradually changing to h⁃CdS. The c/h⁃CdS phase junction formed in the phase transition shows a higher photocatalytic activity than the pure c⁃CdS and h⁃CdS, and the appropriate six⁃square phase content is more beneficial to improve the photocatalytic performance of the heterogenous sample. The results of surface photovoltage show that the formation of heterojunction can significantly improve the photoelectron⁃hole separation efficiency, thus promoting the photocatalytic performance of c/h⁃CdS phase junction. In the experiment of the sacrificial agent, the active species in the CdS photocatalytic reaction is ·O2-.

Key words: Clacination, CdS, Phase transformation, Photocatalytic performance

摘要： 以醋酸镉和硫代乙酰胺为原料，首次通过固相法成功制备了立方/六方硫化镉(c/h⁃CdS)异相结催化剂。利用XRD、SEM和SPV等测试手段对合成的催化剂进行表征。以可见光为光源，评价了该催化剂光催化降解罗丹明B(RhB)的活性，考察了焙烧温度对CdS光催化性能的影响，探讨了降解过程机理。结果表明，随着焙烧温度的增加，CdS逐渐发生立方相硫化镉(c⁃CdS)向六方相硫化镉(h⁃CdS)的转变，相变过程中形成的c/h⁃CdS异相结比纯c⁃CdS和h⁃CdS具有更高的光催化活性，而且适当的六方相含量更有利于提高异相结样品的光催化性能。表面光电压的结果表明，异相结的形成可以显著提高光生电子⁃空穴的分离效率，从而促进了c/h⁃CdS异相结的光催化性能。牺牲剂实验结果表明，在CdS光催化反应中的活性物种为·O2-。

关键词: 焙烧, CdS, 相变, 光催化