摘要
采用低温水热法制备了一系列不同CdS含量的ZnWO4-CdS复合可见光催化剂,通过X射线衍射(XRD)、透射电子显微镜(TEM)、紫外-可见(UV-vis)吸收光谱等手段对合成的催化剂进行了表征。以可见光为光源,评价了该催化剂光催化降解次甲基蓝的活性,考察了CdS的复合量、溶液的pH、染料的种类等对ZnWO4-CdS光催化性能的影响,探讨了降解过程的机理。结果表明:复合物ZnWO4-CdS的光催化效果明显优于纯ZnWO4;当CdS与ZnWO4的摩尔比为0.3时,其光催化效率最高。此外,ZnWO4-CdS在碱性环境中的催化降解效果优于酸性和中性环境,或许与催化剂表面带负电荷有关;活性物质捕获剂实验显示次甲基蓝的光催化降解是光生电子、空穴、羟基自由基共同作用的结果。催化剂重复使用3次后,催化降解效果无明显降低,表明催化剂性能稳定。
Visible light photocatalysts ZnWO4-CdS with different CdS content were successfully synthesized by hydrothermal process at the lower temperature.The obtained products were characterized via X-ray powder diffraction （XRD）,transmission electron microscopy （TEM）,and UV-Vis absorption spectrum.ZnWO4-CdS composite as photocatalyst was investigated for degradation of methylene blue solution under visible light.Some influence factors on the photocatalytic property of ZnWO4-CdS,such as the CdS doped amount,pH,and the type of dyes,were also investigated in detail.The results showed that ZnWO4-CdS composites exhibited the enhanced photocatalytic activities compared with sure ZnWO4 nanorods.The sample M0.3 （CdS doping concentration was 0.3）displayed the best activity for degradation of methylene blue.The photocatalytic efficient of sample M0.3 in alkaline solution was higher than that of middle or acidic solution.Furthermore,the photocatalytic reaction mechanism was simply discussed.Experiments suggested that the active substance generated electrons and holes,together with hydroxyl radical were participated in the photocatalytic process.The activity of photocatalyst M0.3 does not significantly decrease after three cycles.
出处
《中国钼业》
2013年第6期34-39,共6页
China Molybdenum Industry
基金
国家自然科学基金(21171002)
安徽省自然科学基金(11040606M55)
安徽省教育厅自然科学基金(KJ2010A015)资助
安徽省高等学校"十五"优秀人才建设经费资助
