可见光驱动Ag3PO4催化降解罗丹明B和甲基橙

采用简易离子交换法制备可见光驱动Ag3PO4光催化剂.通过X射线衍射、场发射扫描电子显微镜、N2吸附-脱附、紫外-可见漫反射光谱及傅里叶变换红外光谱对所制备的Ag3PO4催化剂进行表征.结果表明,在可见光照射下,Ag3PO4催化剂对罗丹明B降解表现出优越的光催化活性,但对甲基橙的降解活性低,这归因于Ag3PO4催化剂对甲基橙分子吸附量低.可见光照Ag3PO4反应体系中,空穴和超氧自由基共同发挥作用导致罗丹明B和甲基橙光催化降解.在罗丹明B的协助作用下,Ag3PO4催化剂对甲基橙的可见光催化降解活性大大增强,这是由于罗丹明B的存在可产生更多的超氧自由基,从而使甲基橙进一步降解.

Photodegradation of rhodamine B and methyl orange by Ag3PO4 catalyst under visible light irradiation

A visible-light-driven Ag₃PO₄ catalyst was successfully synthesized by a facile ion-exchange route. The as-synthesized Ag₃PO₄ was characterized by X-Ray diffraction (XRD), field-emission scanning electron microscopy, N₂ adsorption-desorption, UV-Vis diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. Under visible light irradiation, the Ag₃PO₄ catalyst showed excellent photocatalytic activity for rhodamine (RhB) degradation, but was poor at degrading methyl orange (MO) because of lower adsorption of MO molecules onto the surface of the Ag₃PO₄. The photodegradation of RhB and MO was achieved by holes and O₂^·- radical attack in the Ag₃PO₄ suspension. The photodegradation of MO over the Ag₃PO₄ catalyst was greatly enhanced in the presence of RhB owing to greater production of O₂^·- radicals.