Preparation Of Sn,ag And Cu Doping Modified TiO₂/WO₃/CNTs And Its Photocatalyst Properties Research

As TiO₂ has a larger band gap and prone to aggregation,the photogenerated electrons and holes are easier to composite reducing of light quantum yield,all of these reasons restrain the application of TiO₂ photocatalytic materials.In order to solve the above problems,this paper has prepared composites photocatalytic materialswith small particle size,large specific surface area and small band gap,through the method which doping with the metal elements Sn,Ag,Cu and co-composite with CNTs and WO₃.Meanwhlie,their characteristics were investigated by XRD,UV-vis DRS,BET,SEM,TEM and photocatalytic degradation for Rhodamine B.1.In the series of Sn doped Sn-TiO₂ and Sn-TiO₂/WO₃/CNTs catalysts system,all of the photocatalysts that belongs to the nanoparticle are anatase.Doping of Sn with a small amount of WO₃,CNTs could inhibit the growth of the grain.At the same time,the doping of tin could narrow the band gap of TiO₂,widen the light response range,absorption in the region of 300-600 nm increased significantly while Sn doping amount was 2%;The aperture of composites is mainly distributed in the 5-15 nm,pore size and shape distribution is uniform,and no obvious aggregation appear.The photocatalytic test results show that the photocatalytic degradation rate of composite catalyst Sn-TiO₂/WO₃,Sn-TiO₂/CNTs,and Sn-TiO₂/WO₃/CNTs were 62.3%,85.2%,98.2%;Cycle stability experimental results show that using 2Sn-TiO₂/WO₃/CNTs degradation of Rhodamine B four time,the degradation rates were aboved 80%.2.The grain size of Ag-TiO₂/WO₃/CNTs composite catalyst is less than TiO₂;When the doping amount of Ag is 5%,the Ag-TiO₂/WO₃/CNTs particle least size is 6.9nm and the specific surface area reached the maximum value of 117.08m2?g-1,the best photocatalytic efficiency is 97.9%,the degradation rate coefficient of 0.06325min-1.CNTs and WO₃ could set as a media or bridge in connection with TiO₂ cluster because of agglomeration,will boost TiO₂ composite agglomeration.The photocatalytic degradation test results show that the photocatalytic degradation rate of composite catalyst Ag-TiO₂,Ag-TiO₂/WO₃,Ag-TiO₂/CNTs,Ag-TiO₂/WO₃/CNTs were 53.4%,70.8%,90.4% and 97.9%;Cycle stability experimental results show that using 5Ag-TiO₂/WO₃/CNTs photocatalyti degradation of Rhodamine B four time,the degradation rates were 97.9%,93.0%,88.0% and 83.0%,respectively.3.When the Cu doped amount was 1%,the minimum Cu-TiO₂/WO₃/CNTs composite catalysts particle is 8.9nm,,the specific surface area reaches the maximum value is 122.1m2?g-1,photocatalytic efficiency reaches the best of 95.2%,and the degradation rate coefficient reaches the maximum value of 0.05614min-1.The photocatalytic degradation test results show that the degradation rate of composite catalyst Cu-TiO₂,Cu-TiO₂/WO₃,Cu-TiO₂/CNTs,Cu-TiO₂/WO₃/CNTs were 58.0%,72.3%,89.0% and 95.2%;Cycle stability experimental results show that using Cu-TiO₂/WO₃/CNTs degradation of Rhodamine B four time,the degradation rates of different samples were 95.2%,90.1%,85.4%,81.0%,respectively.