碘化银/硅藻土光催化剂的制备及可见光催化性能研究

Synthesis of AgI/diatomaceous earth composite photocatalysts with superior photocatalytic performance under visible-light irridiation

采用沉积-沉淀法制备了碘化银/硅藻土复合光催化剂。利用X射线衍射(XRD)、扫描电镜(SEM)、紫外-可见漫反射光谱(UV-vis DRS)、红外光谱(FT-IR)技术对产物进行了表征。研究了碘化银/硅藻土复合光催化剂在可见光下对罗丹明B(RhB)的降解性能。通过循环使用考察了碘化银/硅藻土复合光催化剂的稳定性。结果表明:相比于碘化银和硅藻土,碘化银/硅藻土复合光催化剂的光催化性能显著提高,当碘化银与硅藻土质量比为5%时,其催化效率最高,约为79.19%。机理研究表明,h^+和·O_2^-在降解罗丹明B过程中为主要活性成分。

AgI/diatomaceous earth composite photocatalysts were prepared by deposition-precipitation method.The as-synthesized samples were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,UV-Vis diffuse spectroscopy（UV-vis） and FT-IR spectroscopy（FT-IR）.The photocatalytic activity and stability of the prepared samples were evaluated by the degradation of RhB under the visible light irradiation.Moreover,the recycling tests and trapping experiments were performed to investigate its stability and photocatalytic mechanism.The results showed that the AgI/diatomaceous earth composite with the mass ratio of AgI to diatomaceous earth of 5% obtained the highest activity,and the RhB degradation efficiency reached 79.19%.The main active species were revealed to be h~＋ and·O_2^-.