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利用微波法合成纳米尺寸Ag@AgBr表面敏化K2Ti4O9的复合光催化剂(Ag@AgBr/K2Ti4O9),并通过SEM、X-射线能量色散谱(EDX)、TEM、选定区域电子衍射(SAED)、XRD、紫外-可见漫反射(UV-VisDiffuseReflectance)、XPS等对其进行了表征,同时在可见光下测定催化剂对有机物降解的光催化活性。结果表明,粒径为0.2~0.5μm的Ag@AgBr均匀分散在K2Ti4O9表面,Ag@AgBr/K2Ti4O9对可见光有很好的吸收且Ag@AgBr的担载量影响可见光的吸收。当Ag@AgBr的担载量为25wt%时,复合光催化剂具有最高的光催化活性,光照1h对罗丹明B(RhB)的降解率可达97%。另外,催化剂的担载量和稳定性也做了考察。催化剂较高的光催化活性主要归因于Ag纳米粒子的表面等离子体效应和有效的光生电子-空穴的分离。
The composite Ag (Ag @ AgBr / K2Ti4O9) nanosize Ag @ AgBr surface-sensitized K2Ti4O9 was synthesized by microwave method. The photocatalysts were characterized by SEM, EDX, TEM, XRD, UV-Vis Diffuse Reflectance and XPS were used to characterize the photocatalytic activity of the catalyst. The results show that Ag @ AgBr with a particle diameter of 0.2 ~ 0.5μm is uniformly dispersed on the surface of K2Ti4O9. Ag @ AgBr / K2Ti4O9 absorbs visible light very well and the loading of Ag @ AgBr affects the absorption of visible light. When Ag @ AgBr was loaded at 25wt%, the composite photocatalyst had the highest photocatalytic activity, and the degradation rate of RhB was 97% at 1h. In addition, the catalyst loading and stability are also investigated. The higher photocatalytic activity of the catalyst is mainly due to the surface plasmon effect of Ag nanoparticles and the efficient photo-generated electron-hole separation.