BiO_(2-x)/Bi_(2)WO_(6)的制备及其超声辅助光催化降解四环素的研究

Preparation of BiO_(2-x)/Bi_(2)WO_(6) and study on its application in ultrasonic assisted photocatalytic degradation of tetracycline

采用水热合成法和超声机械混合法制备了不同质量比的BiO_(2-x)/Bi_(2)WO_(6)。对催化剂进行了结构及光电化学性能表征,并在可见光下用超声波研究了其对四环素的降解效果。结果表明,当m(BiO_(2-x))∶m(Bi_(2)WO_(6))=2∶1时,BiO_(2-x)/Bi_(2)WO_(6)光催化剂表现出的光催化活性最高,并且在超声和可见光联合作用下其对四环素降解的时间会大大缩短。经过6次循环试验之后,BiO_(2-x)/Bi_(2)WO_(6)仍然表现出较高的稳定性。催化剂活性的增加归因于超声波的机械混合作用,超声波将层状BiO_(2-x)分散在球形Bi_(2)WO_(6)上,加速了电子转移和分离。

BiO_(2-x)/Bi_(2)WO_(6)with different mass ratio is prepared by means of hydrothermal method and ultrasonic mechanical mixing method.The structure and photoelectrochemical characterization of the catalyst is carried out,and the degradation of tetracycline over the catalyst is studied by ultrasonic wave under visible light.The results indicate that BiO_(2-x)/Bi_(2)WO_(6)photocatalyst with a molar ratio of 2∶1 between BiO_(2-x)and Bi_(2)WO_(6)has the highest photocatalytic activity,over which the degradation time of tetracycline can be greatly shortened when ultrasound and visible light are combined.After 6 cycles of experiments,BiO_(2-x)/Bi_(2)WO_(6)still shows high stability.The increase in catalyst activity is attributed to the mechanical mixing of ultrasonic waves,which can disperse the layered BiO_(2-x)on the spherical Bi_(2)WO_(6),and accelerate the transfer and separation of electron.