β-Bi_2O_3修饰Bi_2WO_6光催化降解苯酚及其可能机理  

Improved Photocatalytic Degradation of Phenol over β-Bi_2O_3 Modified Bi_2WO_6 and Possible Mechanism

作　　者：李晓金[1] 盛珈怡 陈海航[1] 许宜铭[1] 

机构地区：[1]浙江大学化学系,硅材料国家重点实验室,杭州310027

出　　处：《物理化学学报》2015年第3期540-544,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21377110);国家重点基础研究发展规划项目(973)(2011CB936003)资助~~

摘　　要：采用简单混合法制备了一系列Bi2O3/Bi2WO6复合光催化剂.在紫外光降解水中苯酚的过程中,Bi2O3/Bi2WO6的光催化活性随Bi2O3含量的增加呈现先增大后减小的趋势.当Bi2O3最佳负载量等于12.5%(质量分数,w)时,该复合光催化剂的活性大约是单一Bi2WO6的4倍.固体样品表征表明,Bi2O3主要以β-Bi2O3存在,复合光催化剂是Bi2O3和Bi2WO6的简单混合物.此外,在电催化氧化水的过程中,β-Bi2O3/Bi2WO6薄膜电极的光电流远大于β-Bi2O3和Bi2WO6薄膜电极的光电流之和.Bi2O3对Bi2WO6光催化的促进作用是由于前者接受后者的光生空穴,提高Bi2WO6光生载流子的分离效率,从而加快了O2的还原和苯酚的降解.In this study, a series of Bi2O3- containing Bi2WO6 catalysts were prepared by a simple mixing method. We used the oxidation of phenol in water under UV light as a model reaction, and found that as the amount of Bi2O3 in the mixture increased, its photocatalytic activity increased, and then started to decrease. A maximum activity was observed with the catalyst containing 12.5%（mass fraction, w） of Bi2O3, about 4 times that of Bi2WO6. Solid characterization revealed that the composite was a mixture of β-Bi2O3 and Bi2WO6. The water oxidation photocurrent over the β-Bi2O3/Bi2WO6 thin film electrode was much larger than the sum of the photocurrents of the β-Bi2O3 and Bi2WO6thin film electrodes. It is proposed that there is a valence hole transfer from Bi2WO6 to β-Bi2O3, which improves the charge separation efficiency, and consequently increases the rate of phenol degradation.

关 键 词：氧化铋 钨酸铋 光催化 电荷转移 有机物降解 

分 类 号：O643.36[理学—物理化学]