WO_(3)/Ag_(3)PO_(4)复合物的制备及其光催化性能研究

Preparation of WO_(3)/Ag_(3)PO_(4) Composite and Its Photocatalytic Performance

为了提高WO_(3)的光催化性能,本文采用机械混合法制备了一系列不同Ag_(3)PO_(4)含量的WO_(3)/Ag_(3)PO_(4)复合物样品,并通过X-射线粉末衍射、扫描电子显微镜、紫外-可见漫反射光谱和X-射线光电子能谱进行了表征。在可见光(λ>400 nm)照射下,通过光催化1,4-二氢-2,6-二甲基吡啶-3,5-二羧酸二甲酯(1,4-DHP)的氧化脱氢反应考察了WO_(3)/Ag_(3)PO_(4)复合物的光催化性能。结果表明:WO_(3)/Ag_(3)PO_(4)复合物的光催化活性明显高于纯WO_(3)和Ag_(3)PO_(4);可见光照射30 min后,WO_(3)/Ag_(3)PO_(4)对1,4-DHP的氧化脱氢效率最高可达97.3%。在1,4-DHP的光催化氧化脱氢过程中,光生空穴为主要的活性物种,超氧负离子自由基起次要作用。本研究提供了一种增强光催化剂活性的简单方法。

This paper prepares a series of WO_(3)/Ag_(3)PO_(4)composites with different Ag_(3)PO_(4)proportions by a mechanical mixing method for improving the photocatalytic performance of WO_(3).In addition,it is characterized by X-ray powder diffraction,scanning electron microscopy,ultraviolet-visible diffuse reflectance and X-ray photoelectron spectroscopy.The photocatalytic performance of WO_(3)/Ag_(3)PO_(4)composites is investigated by the oxidative dehydrogenation of 1,4-DHP after photocatalysis.The results show that the photocatalytic activity of WO_(3)/Ag_(3)PO_(4)composites is significantly higher than that of pure WO_(3)and Ag_(3)PO_(4);the highest oxidative degradation rate of 1,4-DHP catalyzed by WO_(3)/Ag_(3)PO_(4)has reached 97.3%after 30 mins of visible light irradiation(λ>400 nm);the main active species is photo-generated hole(h^(+))and superoxide radicals(·O^(-)^(2))have played minor roles in the photocatalytic process of 1,4-DHPoxidative dehydrogenation.This study has provided a simple method for improving the photocatalytic activity.