Deactivation and regeneration of amorphous TiO_2/WO_3 films in photocatalysis

The activity,deactivation,activity regeneration of amorphous TiO2/WO3 films were studied via photocatalytic oxidation of methyl blue.The photodegradation ratio of methyl blue was 93.8% by fresh TiO2/WO3 films.Having been used for six times,the photodegradation ratio was still higher than 85%.For the deactivated films after reused for nine times,four methods were attempted to regenerate the activity,soaking in water or ethanol for 30 minutes and ultrasonic treatment in distilled water or ethanol for 30 minutes,with which the photodegradation ratio could be resumed from 10.3% to 23.2%,28.3%,79.2% and 90.5% respectively.