AgBr@ZnO复合光催化剂的制备及光催化性能和反应动力学模拟

Preparation,photocatalyticperformance of AgBr@ZnO compositephotocatalysts andtheirsimulated degradation kinetics of the as-prepared photocatalysts

利用原位生长法制备了一系列不同AgBr含量的AgBr@ZnO复合光催化剂,采用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见漫反射吸收光谱(UV-Vis)等手段对所制备的光催化剂进行了表征,并考察了AgBr@ZnO在可见光下光催化降解亚甲基蓝溶液的光催化性能。研究表明,AgBr均匀负载在ZnO表面,且复合光催化剂表现出比纯ZnO更高的光催化活性。当复合AgBr含量为10%时,所制备的复合光催化剂的光催化活性最佳,光反应240 min后对MB的降解率可达82.3%。所制备的复合光催化剂可见光下降解亚甲基蓝遵循一级反应动力学。

The AgBr loaded ZnO（AgBr@ZnO） were obtained by in-situ growth method.Thecompositephotocatalysts were characterized by X-ray diffraction（ XRD）,scanning electron microscope（ SEM）,UV-Vis diffuse reflectance spectra（ DRS）. The photocatalytic activity and degradation kinetics of the photocatalysts were studied by the degradation of methyl blue solution under visible light（λ420 nm）irradiation.The results indicated that AgBr were well dispersed on the external surface of the ZnO and the composite photocatalysts exhibit higher photocatalytic activity compared with pure ZnO,and 10% AgBr@ZnO exhibits the best catalytic performance,leading to as much as 82. 3% reduction of MB concentration in 240 min. The reaction of photocat-alytic oxidation is the first order reaction in kinetics.