异质结型KBiO_3/BiOCl光催化剂制备及其可见光光催化性能

Synthesis of heterojunctiontype KBiO_3/BiOCl photocatalyst and its visible light driven photocatalytic activities

铋酸钾具有良好的光催化性能,但稳定性差,通过原位转化法在铋酸钾表面生成氯氧化铋构成KBiO_3/BiOCl异质结光催化剂并将其用于降解结晶紫。实验结果表明,BiOCl能有效改善铋酸钾稳定性并提高其光催化性能,构成的KBiO_3/BiOCl异质结光催化剂可在可见光照下90 min内实现结晶紫完全降解,活性优于KBiO_3或BiOCl。KBiO_3/BiOCl异质结光催化剂可见光性能提高归因于异质结结构对吸收光区的拓宽和对电子-空穴复合率的抑制,以及原位生长的BiOCl比表面积的增大。

Potassium bismuthate is an excellent photocatalyst with dis-satisfactory stability. In this research,a heterojunction KBiO_3/BiOCl photocatalyst is synthesized via in-situ solid-transformation method on the surface of KBiO_3 and used to photo-degrade crystal violet. The results confirm that the in-situ growth of BiOCl improves the stability of KBiO_3 and enhances its photocatalytic performance effectively. Crystal violet can be completely photo-decomposed in 90 minutes with KBiO_3/BiOCl heterojunction under visible light irradiation,which is better than that with pure KBiO_3 or BiOCl. This performance improvement should ascribe to the broadening of light absorption spectrum,suppression of photogenerated electrons and holes recombination because of the constructed KBiO_3/BiOCl heterojunction structure,and the increasing of surface area due to the in-situ growth of BiOCl.