水热法合成ZnO/BiVO4复合光催化剂及其光催化性能

采用水热法制备ZnO/BiVO4复合光催化剂,研究了ZnO复合方式(直接和原位)对合成ZnO/BiVO4光催化剂性能的影响.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、BET、紫外-可见分光光度计等检测手段对产物的晶体结构、微观形貌、比表面积和光吸收特性进行了表征.结果表明:ZnO的复合对产物的组成及形貌均有影响,复合产物中有V2 O5、Bi2 O3生成,但仍以单斜BiVO4为主.与纯BiVO4相比,复合后的BiVO4结晶度变差、粒度变小,但光催化性能提高.采用直接复合法制备的ZnO/BiVO4光催化性能提高更明显,在高压汞灯照射240 min时,亚甲蓝的降解率达90.4;,相同条件下纯BiVO4对亚甲蓝的降解率仅为82.2;.

Hydrothermal Synthesis of ZnO/BiVO4 Composite Photocatalyst and Its Photocatalytic Activity

ZnO/BiVO4 composite photocatalyst was prepared by hydrothermal method , and the influence of ZnO composite method ( directly adding or in-situ forming ) on the performance of ZnO/BiVO4 photocatalyst was studied .The crystal structure , morphology , specific surface area and optical absorption properties of the product were characterized using X-ray diffraction ( XRD ) , scanning electron microsocopy ( SEM) , BET and ultraviolet-visible spectrophotometer .The results show that the ZnO has effects on the phase composition and microstructure of the products , and new phases of V 2 O5 and Bi2 O3 are formed in the products , but the monoclinic BiVO 4 is still the main component .Comparing with the pure BiVO4 , the crystallinity and particle size of the composite become worse and smaller , but the photocatalytic activity of the product is improved . The photocatalytic performances of the samples prepared by direct composite method is improved greatly .The degradation rate of methylene blue is 90. 4; when irradiated for 240 min by high-pressure mercury lamp .The degradation rate of the pure BiVO 4 to methylene blue is only 82 .2;under the same conditions .