The Construction Of La₂BMnO₆（B=Co、Ni、Cu）-ZnO Composite Photocatalysts And The Photocatalytic Activity For Phenol Degradation

In this work,three double perovskites are prepared by sol-del method,including La2CoMnO6、La2CuNiO6 and La2CuMnO6.We choose glucose as our complexing agent.Then we put the perovskites and zinc oxide compound:X%La2CoMnO6-ZnO、X%La2CuNiO6-ZnO and X%La2CuMnO6-ZnO(X%=10%,20%,30%,40%,50%,60%,70%,80%,90%).And we test the photo-degradation of phenol of all samples under visible light.The characterization method including XRD、UV-vis、PL、XPS、BET、SEM、COD and BET.Here are the testing results:1.The La2CoMnO6,ZnO and La2CoMnO6-ZnO composite catalyst were successfully prepared.The results of photocatalytic degradation shows that 40%La2CoMnO6-ZnO has the best activity of photocatalytic degradation,the phenol degradation rate is 86.83%after 5h irradiation.The 40%catalyst is still very stable after 6 recycling runs.The mainly reason is due to the its narrow band gap(2.68eV)and high surface adsorption of active oxygen content(86.83%).In the end,we put forward the mechanism of photocatalytic reaction,according to the characterization results.2.The La2NiMnO6,ZnO and La2NiMnO6-ZnO composite catalyst were successfully prepared.The photocatalytic degradation test screening the best proportion of La2NiMnO6 is 30%.Its phenol degradation rate is up to 93.82%after 5h irradiation.The best catalyst has 81.42%oxygen adsorption on the surface,it is 9.62%higher than the La2NiMnO6,and also 22.25%higher than the ZnO.We found that 30%La2NiMnO6-ZnO is a kind of high efficiency,high removal rate and high stability photocatalyst.The reaction process is in line with the first order reaction kinetics.The calculate of kinetic parameters provides applied basic technical indicators for the industrialization of the catalyst.3.The preparation of La2CuMnO6、ZnO and X%La2CuMnO6-ZnO are successful.20%La2CuMnO6-ZnO has the best photocatalytic activity,the degradation of phenol is reach up to 86.57%after 5h irradiation.The 20%La2CuMn06-ZnO catalyst has 76.11%oxygen adsorption on the surface and its band gap energy is 2.63eV,which is more excellent than La2CuMn06 and ZnO.