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以TiO_2(P25)和α-Bi_2O_3为原料,NaCl-KCl(摩尔比为1∶1)为熔盐,采用熔盐法制备出不同前躯体比例(α-Bi_2O_3/TiO_2)和不同煅烧时间的Bi12TiO20纳米粉体。利用X射线衍射、紫外-可见漫反射和扫描电子显微镜等表征手段对样品进行表征,发现熔盐法制备的粉体具有颗粒均匀和形貌单一等优点。通过在可见光照射条件下降解罗丹明B(RhB)活性的研究,探讨了其光催化能力及降解机理。结果表明:前躯体摩尔比为4,煅烧时间2h制备的纳米粉体具有最好的光催化性能,这主要是因为其具有较规则的暴露晶面和存在的异质结结构,有利于光生电子-空穴对的分离。
TiO 2 (P25) and α-Bi 2 O 3 as raw materials and NaCl-KCl (molar ratio of 1: 1) as molten salt were used to prepare Bi12TiO20 with different ratio of precursor and α-Bi 2 O 3 / TiO 2 Nano-powder. The samples were characterized by X-ray diffraction, ultraviolet-visible diffuse reflectance and scanning electron microscopy. It was found that the powder prepared by the molten salt method has the advantages of uniform particle size and single morphology. The photocatalytic activity and degradation mechanism of RhB were investigated by observing the activity of RhB under visible light irradiation. The results showed that the best photocatalytic activity of nano-powders prepared by the molar ratio of 4 and calcination time 2h was mainly due to the more regular exposed crystal planes and the existing heterojunction structure, - Hole pair separation.