CoWO_(4)/CdS异质结光催化剂的制备及其光催化性能

Preparation and photocatalytic performance of CoWO_(4)/CdS heterojunction photocatalysts

以CdS纳米棒和CoWO_(4)前驱体为原料通过水热法制备了CoWO_(4)/CdS异质结光催化剂。利用X射线衍射、扫描电子显微镜、紫外-可见漫反射光谱和电化学等表征手段对已合成的异质结光催化剂的晶体结构、微观形貌、光学和光电化学性质进行了表征。实验结果表明,CoWO_(4)/CdS异质结构能够有效提高CdS的可见光吸收强度,有效分离光生电子-空穴,使得光催化降解性能大幅度提高。当CoWO_(4)与CdS的质量比为1∶10时,CoWO_(4)/CdS-2具有最高的光催化活性。以有机染料罗丹明B为模拟污染物进行光催化降解实验,可见光照射25 min后CoWO_(4)/CdS-2对罗丹明B的降解率达到97.5%。在经过5次循环使用后,样品仍能保持较高的光催化活性,没有明显衰减。

CoWO_(4)/CdS heterojunction photocatalysts were prepared by hydrothermal method using CdS nanorods and precursor of CoWO_(4) as raw materials.The crystal structure,morphology,optical and photoelectrochemical properties of the as-prepared catalysts were characterized by X ray diffraction,scanning electron microscopy,UV-Vis diffuse reflectance spectroscopy and electrochemical measurements.The experimental results showed that the CoWO_(4)/CdS heterostructure can effectively improve the visible-light absorption intensity of CdS,effectively separate photogenerated electron-holes,and greatly improve the photocatalytic degradation performance.When the mass ratio of CoWO_(4) to CdS was 1∶10,CoWO_(4)/CdS-2 showed the highest photocatalytic activity.The organic dye rhodamine B(RhB)was used as the simulated pollutant for photocatalytic degradation experiment.After 25 min of visible-light irradiation,the degradation rate of RhB by CoWO_(4)/CdS-2 reached 97.5%.After 5 cycling tests,CoWO_(4)/CdS-2 can maintain a high photocatalytic activity without obvious reduction.