摘要
采用沉淀法和热聚合法分别将AgI、氮化碳(CN)负载在介孔γ-Al_2O_3(MA)上,并通过光还原银离子成功制备了等离子体诱导可见光催化剂Ag-AgI/CN/MA.利用X射线衍射(XRD)、X射线光电子能谱(XPS)、场发射扫描电子显微镜(FESEM)、紫外可见漫反射光谱(UV-vis DRS)和透射电子显微镜(TEM)对Ag-AgI/CN/MA复合材料进行表征,并对其在可见光照射下(λ>420 nm)的光催化性能进行了研究,考察了初始溶液pH值及催化剂投加量等条件对光催化反应的影响.结果表明,表面银以Ag+和Ag0形式共存,并且Ag和AgI均匀地分散在CN的表面.与CN和Ag-AgI/MA相比,Ag-AgI/CN/MA复合物对甲基橙(MO)具有更高的可见光催化降解效率,且反应过程中Ag+的释放量显著减少,显示出良好的稳定性.当溶液pH值为7、催化剂投加量为1 g·L^(-1)时,Ag-AgI/CN/MA-2显示出最优的催化性能.同时,其对罗丹明B(Rh B)、甲基红(MR)和刚果红(CR)等不同电性的染料均体现出良好的催化性能.
Ag-AgI/CN/MA photocatalysts were prepared by coupling graphitic carbon nitride( CN) with AgI/γ-Al2O3( AgI/MA)through a thermal polymerization method and Ag nanoparticles were deposited by photoreduction. The catalysts were characterized by Xray diffraction( XRD),X-ray photoelectron spectroscopy( XPS),field emission scanning electron microscopy( FESEM),UV-vis diffuse reflectance spectra( UV-vis DRS),and transmission electron microscopy( TEM). The photocatalytic performance of different catalysts was evaluated under visible light irradiation( λ 420 nm). The effects of different conditions such as pH and catalyst dosage on photoreactions were also investigated. The results showed that Ag+and Ag0 coexisted on the surface of the catalyst and Ag and AgI nanoparticles were uniformly distributed on the surface of CN. Compared with CN and Ag-AgI/MA,Ag-AgI/CN/MA composites exhibited better visible-light photocatalytic activity and stability,and the release of silver ions was significantly suppressed. At the catalyst dosage of 1 g·L^-1and pH = 7,Ag-AgI/CN/MA-2 exhibited the optimal photocatalytic performance. Ag-AgI/CN/MA-2 also showed high photoactivity for the degradation of dyes with different charges,such as rhodamine B( Rh B),methyl red( MR) and congo red( CR).
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第10期4245-4252,共8页
Environmental Science
基金
国家自然科学基金项目(51538013)
国家重点研发计划项目(2016YFA0203200)