【摘要】 采用溶胶-活性炭浸渍法制备了Bi-Ti-O体系光催化剂,并以XRD、SEM、UV-Vis DRS对其进行表征。以在紫外光照射下对甲基橙的降解评价其光催化活性,分别考察了不同Bi/Ti比及煅烧温度的影响。实验表明,其光催化性能由粒径、吸光性能等共同影响。煅烧温度的提高使其在紫外区吸光性能有所下降,光催化活性相应降低。随着Bi含量的增加,在500℃时其禁带宽度有增加趋势,其形貌也发生了较大变化。而温度的升高,也使样品逐渐烧结团聚,降低了其光催化活性。在Bi/Ti比为5∶5和7∶3,煅烧温度为500℃时,由于Bi2O3、Bi2Ti2O7和Bi4Ti3O12三相共生共存,其混晶效应使得在紫外区的吸收明显增强,相应地提高了光催化活性。更多还原

【Abstract】 Bi-Ti-O serial oxides were prepared by the active carbon-assisted-sol method,and were characterized by XRD,SEM and UV-Vis DRS.Their photocatalytic properties were examined by using the methyl orange as the model compound and UV light as light source.The performances of catalysts with different Bi/Ti proportions and calcining heat were determined as well.It’s showed that the photon adsorption properties are reduced in ultraviolet band with the rise of temperature.The band gap energies of samples prepared under 500℃ have a tendency of decreasing as the content of Bi increase.The products prepared at 500℃ with Bi/Ti proportion of 1∶ 9 and 3∶ 7 are shown composed by nearly spherical-shaped crystalline particles.The particle morphologies change greatly from nanometer to micron as the Bi/Ti proportion goes up.The agglomeration and sintering at higher temperature lower their activities.With the Bi/Ti proportion of 5∶ 5 and 7∶ 3,calcinated at 500℃,the photon adsorption in ultraviolet band is enhanced evidently due to mixed crystal effect,which caused by the co-exist of Bi2O3,Bi2Ti2O7 and Bi4Ti3O12.更多还原