二氧化铈/钼酸铋复合光催化剂的制备及光催化性能

采用水热法一步合成二氧化铈/钼酸铋复合材料,进一步探究了不同酸碱性反应体系溶液中二氧化铈与钼酸铋的组成、结构和光催化性能的关系。运用X射线衍射分析仪、扫描电子显微镜、傅里叶变换红外光谱仪、紫外-可见漫反射光谱仪等对样品进行表征。研究发现CeO_2的加入与钼酸铋在不同酸碱性合成体系合成产物的形态、组成、结构及光催化性能息息相关。未加Ce~(3+)前,在酸性条件下反应生成的是Bi_2MoO_6;在碱性条件下的反应产物是Bi_(3.64)Mo_(0.36)O_(6.55)/Bi_2MoO_6复合材料。当合成的反应溶液体系中引入CeO_2之后,在酸性条件下反应生成的Bi_2MoO_6催化性能最好;在碱性条件下,反应生成的是Bi_(3.64)Mo_(0.36)O_(6.55)。因此,在碱性条件下,CeO_2的加入能够促进Bi_2MoO_6转化Bi_(3.64)Mo_(0.36)O_(6.55)。

Preparation and Photocatalytic Activity of Cerium Oxide/Bismuth Molybdate Composite Photocatalyst

Cerium oxide/Bismuth molybdate catalysts were synthesized by hydrothermal method. The relationships between cerium oxide and the composition, structure, photocatalytic activity of Bismuth molybdate were further investigated under the different acid-base reaction system solutions. The samples were characterized by X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy. It was found that the addition of CeO₂ seriously affected the morphology, composition, structure and photocatalytic properties of bismuth molybdate in different acid-base synthesis systems. The reaction product was more beneficial to the formation of Bi₂MoO₆ in the acidic system and made for the formation of Bi_3.64Mo_0.36O_6.55/Bi₂MoO₆ in alkaline condition without CeO₂. When CeO₂ was added to reaction-solution system, the composition and structure of the substances were almost unchanged in the acidic system; the photocatalytic activity was greatly enhanced. The morphology, composition, structure and photocatalytic properties of the materials have changed greatly under alkaline conditions. The reaction product was more beneficial to the formation of Bi_3.64Mo_0.36O_6.55. Therefore, under alkaline conditions, the addition of CeO₂ promoted the conversion of Bi₂MoO₆ to Bi_3.64Mo_0.36O_6.55.