纳米Ag/ZnO光催化剂及其催化降解壬基酚聚氧乙烯醚性能

采用氨浸法制备了不同Ag负载量的纳米Ag/ZnO光催化剂,并用X射线衍射、比表面积测定、X射线光电子能谱和漫反射紫外-可见光谱测定了Ag/ZnO的晶型结构、比表面积、表面组成和光谱特征.以壬基酚聚氧乙烯醚(NPE-10)为模型污染物,分别在紫外光和可见光照射下考察了纳米Ag/ZnO的光催化活性.结果表明,Ag能成功地负载到ZnO表面,且随着Ag负载量的增加,ZnO的粒径逐渐增大,比表面积逐渐减小.与纳米ZnO样品相比,Ag/ZnO中Ag 3d5/2结合能减小,而Zn 2p和O 1s结合能增大,ZnO表面的羟基氧和吸附氧含量增加.当Ag负载量大于0.5%时,Ag/ZnO样品的吸收光谱发生红移,在可见光区出现吸收.光催化降解结果表明,0.5%Ag/ZnO样品的光催化活性最高,在紫外光和可见光照射3 h后NPE-10降解率分别约为77%和56%,而ZnO样品的光催化活性仅约为61%和40%.

Nano-Ag/ZnO Photocatalyst and Its Catalytic Performance for Degradation of Nonylphenol Ethoxylate-10

Ag-modified nano-ZnO samples with different Ag loadings were prepared by the ammonia immersion method.The crystal structure,specific surface area,surface composition,and spectral characteristics were analyzed by X-ray diffraction,N2 adsorption,X-ray photoelectron spectroscopy,and diffuse reflectance ultraviolet-visible spectroscopy,respectively.The photocatalytic activity of Ag/ZnO samples for degradation of nonylphenol ethoxylate-10(NPE-10) was studied under the irradiation with ultraviolet light and visible light.The results showed that Ag could be successfully supported on the nano-ZnO surface.The particle size of Ag/ZnO increased and its specific surface area decreased with the increase of Ag loading.Compared with the nano-ZnO,the binding energy of Ag 3d5/2 in Ag/ZnO dropped,but the binding energy of Zn 2p and O 1s increased.The contents of adsorbed oxygen and hydroxy oxygen on the Ag/ZnO surface increased remarkably in contrast to that of the pure ZnO sample.The 0.5%Ag/ZnO exhibited a red shift in the absorption spectrum.The photocatalytic activity of the 0.5%Ag/ZnO sample was the highest,and the degradation rate of NPE-10 was 77% and 56% under 3 h irradiation of ultraviolet light and visible light,respectively.