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 ofβ-Bi2O3 and Bi2WO6. The water oxidation photocurrent over theβ-Bi2O3/Bi2WO6 thin film electrode was much larger than the sum of the photocurrents of theβ-Bi2O3 and Bi2WO6 thin film electrodes. It is proposed that there is a valence hole transfer from Bi2WO6 toβ-Bi2O3, which improves the charge separation efficiency, and consequently increases the rate of phenol degradation.
展开▼
