超声协同TiO_2光催化降解4,4′-二溴联苯

TiO_2 sonophotocatalytical synergistic degradation of 4,4′-dibromobiphenyl

以纳米TiO2膜为光催化剂,对4,4′-二溴联苯水溶液进行了超声光催化(US+UV)、光催化(UV)和超声(US)降解,探讨了初始浓度、超声的声强和频率等对降解4,4′-二溴联苯的影响。结果表明,4,4′-二溴联苯的超声光催化降解存在协同效应,降解率随4,4′-二溴联苯初始浓度的增大而下降,随声强和频率的增大而增大。超声光催化过程符合一级动力学方程,反应数率常数为0.011 min-1。超声光催化与光催化的降解产物不同。

The combination of ultrasound（US） and ultraviolet irradiation（UV） with TiO2 film as the photocatalyst was used to degradate 4,4′-dibromobiphenyl（4,4′-DBB）.The influence of initial 4,4′-DBB concentration,ultrasonic frequency and intensity on degradation was investigated.And the mechanism of degradation of 4,4′-DBB was discussed.The result showed that US/UV/TiO2 technique was considerably more effective than US or UV alone,and ultrasound and ultraviolet light exhibited synergistic effect.The 4,4′-DBB degradation rate decreased with the increase of initial 4,4′-DBB concentration,and the degradation rate increased with the increase of ultrasonic frequency and intensity.The sonophotocatalytic degradation of 4,4′-DBB in the presence of TiO2 catalyst followed a pseudo first-order kinetics.The reaction rate constant was 0.011 min^-1.