掺杂型Bi2WO6光催化剂的制备及其光催化性能研究

复合氧化物Bi2WO6可作为一种高效的光催化材料，但Bi2WO6的光生电子空穴对复合率高，分离困难，导致对光的吸收能力下降，光催化效率降低。金属Cu和Ag是良好的光催化剂助剂，能有效降低光催化剂的光生电子空穴对复合率，改善催化剂的光吸收性能。采用水热法制备金属Cu和Ag掺杂的可见光催化剂Bi2WO6，并进行X射线衍射、扫描电子显微镜、紫外-可见光谱和比表面积表征。结果表明，掺杂的金属离子并未进入Bi2WO6晶格内部，只是负载于Bi2WO6表面。掺杂金属后，Bi2WO6的吸收边带变宽,吸光强度变强，比表面积显著增加。以模拟含酚废水为处理对象，考察掺杂型Bi2WO6对苯酚光催化降解效果的影响。实验结果表明，Cu-Bi2WO6光催化剂在光照作用下对苯酚有降解作用，随着光照时间的延长，苯酚的降解程度不断提高，在空气通入量为25 mL·min-1和400 W金卤灯下光照180 min，Cu-Bi2WO6和Ag-Bi2WO6对10 mg·L-1的模拟含酚废水基本降解完成。

Preparation and photocatalytic performance of doping Bi2WO6 photocatalysts

Abstract：Composite oxide Bi2WO6 is a type of efficient photocatalytic matenat, out its ability declines because of high recombination rate of photogenerated electron hole pair and difficult sepa- ration, so its photocatalytic efficiency is reduced. As the additives of the photocatalyst, Cu and Ag metals can effectively reduce the recombination rate of photogenerated electron hole pair, thereby improving the catalyst light absorption properties. Cu and Ag doping Bi2WO6 photocatalysts were prepared by hydrother- real method and characterized by XRD, UV-Vis DRS, SEM and BET. The results showed that metal ions did not entered into the lattice of Bi2WO6, but were supported on the surface of BizWO6. After doping metals, Bi2WO6 photocatalysts had significant red-shift in the absorption band, and their absorption inten- sity .in the visible region and surface area increased obviously. The photocatalytic performance of doping Bi2WO6 photocatalysts for the degradation of phenol was investigated. The experimental results showed that with the prolonging of illumination time, the degradation of phenol under the visible light was increased. The phenol-containing wastewater （ 10 mg · L-1 ） over Cu-BizWO6 and Ag-Bi2WO6 catalysts was degraded completely under the condition as follows ： air flow rate 25 mL ·min-1, illumination time 180 min and 400 W metal halide lamp.