增强光催化活性的3D分级结构Bi2W06微球及表面酸性

以KNO3为矿化剂，用水热法制备了3D分级结构Bi2WO6微球，通过XRD、SEM、BET对产物进行了表征．探讨了3D分级结构Bi2WO6微球可能的形成机理．以罗丹明B为模型污染物，研究了合成产物的光催化性质．结果表明：在紫外光下，RhB的降解以共轭结构断裂的光催化反应为主；而在可见光照射下，RhB的降解可能是光催化和光敏化共同作用的结果．进一步以吡啶为探针分子，通过吸附吡啶红外光谱探讨了Bi2W06表面酸性与光催化降解RhB之间的关系．研究显示，Bi2W06具有较强的表面酸性，增强了Bi2WO6与RhB分子之间吸附作用，有利于染料分子上的电子跃迁至催化剂上，易于发生光敏化和光催化反应。

Photocatalytic activity enhancement for 3D hierarchical Bi2WO6 microsphere and surface acidity

Three-dimensional （3D） hierarchical BiaWO6 microsphere has been synthesized by a facile hydrothermal method using KNO3 as mineralizer. The obtained products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, N： adsorption/desorption （BET） in detail. A possible formation mechanism of Bi2WO6 microsphere was proposed. The photocatalytic activity of the as-synthesized sample for RhB was studied. It was found that under UV light irradiation, RhB degradation was predominated via the photocatalytic process which included the destruction of conjugated ring structure; while under visible light irradiation, RhB degradation might be attributed to the photocatalytic and the photosensitized process. By pyridine adsorption, the surface acidity of catalyst Bi2WO6 was measured using infrared spectroscopy. The relationship between surface acidity of Bi2WO6 and photocatalytic degradation of RhB was explored. It was found that the more surface acid sites of Bi2WO6, the stronger adsorption between RhB and Bi2WO6. Consequently, the photogenerated electrons on the dye could more easily transfer to the photocatalyst, leading to the photosensitization and photocatalysis.