The Study of Lanthanum-Doped SnO₂ Photocatalytic Materials and Their Properties

Tin dioxide (SnO₂) is an N-type semiconductor material, which has a potential application prospect in photocatalysis. The band gap width and electronic structure of tin dioxide can be changed by proper doping treatment, and its photocatalytic performance can be further improved. Using stannous tetrachloride pentahydrate, dodecylamine, oleic acid and lanthanum oxide as raw materials, tin dioxide nano-powders with different lanthanum doping amounts were synthesized by solvothermal method. XRD, SEM and EDS were used to characterize the samples, and the effects of different lanthanum oxide doping amounts on the morphology and structure of tin dioxide powder were investigated. Using Rhodamine B solution as the simulated pollutant, the effects of La doping, Rhodamine B initial concentration and photocatalyst dosage on the photocatalytic performance of tin dioxide powder were studied. The results show that lanthanum is successfully incorporated into SnO₂, and no other impurities are introduced in the synthesis of lanthanum doped SnO₂, which is a single tetragonal phase; and The electronic structure of SnO₂ is changed by lanthanum doping, and the band gap width of SnO₂ is reduced to 3.2ev by 5% lanthanum doping. The doping of lanthanum oxide can promote the photocatalytic performance of tin dioxide. When the doping amount is 5%, the degradation rate of Rhodamine B reaches the highest, that is, the degradation rate of Rhodamine B is 100% when the sample with the doping amount of lanthanum 5% is added to 10mg/L Rhodamine B with 80mg to 100ml.