纳米复合可见光催化剂Ag3PO4/凹凸棒石的制备及其性能研究

Preparation and photocatalytic activity of Ag_3PO_4/attapulgite nano-composite photocatalyst under visible light

采用化学沉淀法将高分散纳米Ag_3PO_4颗粒负载到纯化的凹凸棒石(ATP)表面,得到了具有可见光响应、高活性的纳米复合可见光催化剂Ag_3PO_4/ATP。采用X射线衍射、扫描电子显微镜、紫外—可见漫反射光谱、红外吸收光谱、热重和比表面积分析等技术对催化剂的相结构和微观形貌等进行了表征。结果表明,ATP因其具有较大的负载表面使得负载的Ag_3PO_4纳米颗粒变小、分散程度增强且光吸收边红移,增加了Ag_3PO_4/ATP的活性位点。可见光条件下,当Ag_3PO_4负载量为45%(质量分数)时,Ag_3PO_4/ATP对亚甲基蓝的准一级动力学表观速率常数是Ag_3PO_4的2.39倍。

The Ag3PO4/attapulgite（ ATP） photocatalysts composited by highly dispersed Ag3PO4 nanoparticles and purification ATP were prepared by a chemical precipitation method,which were sensitive to visible light and high activity.The photocatalysts were characterized by X-ray power diffraction,scanning electron microscope,UV-visible diffuse reflectance spectrometer,Fourier-transform infrared spectroscopy,thermogravimetric analyses and Brunauer-Emmet-Teller techniques to determine their phase structures and micromorphologies. The results showed that the high surface area of ATP promoted the dispersibility of Ag3PO4 nanoparticles with smaller size and absorption edge red-shift,which increased the reactive sites of Ag3PO4/ATP. When the loading amounts of Ag3PO4 nanoparticles nearly reached to 45%（ mass fraction）,the pseudo-firstorder kinetic rate constant of composited photocatalysts to photocatalytic degradation of methylene blue mas 2. 39 times of pure Ag3PO4 under the visible light.