Photocatalytic activity and stability of TiO_2 and WO_3 thin films

摘要

Photocatalysis represents a viable option for complete degrading the dye molecules resulted in the textile industry, up to products that do not represent environmental threats. The photocatalytic degradation of methyl orange has been investigated using TiO_2, WO_3 and mixed thin films. The photodegradation efficiency is examined in correlation with the experimental parameters (irradiation time, H_2O_2 addition and stability), along with the morphology and crystallinity data. The H_2O_2 addition increases the photodegradation efficiency by providing additional hydroxyl groups and further reducing the recombination of the electron-hole pairs by reacting with the electrons at the catalyst interface. To test the stability of the photocatalytic films in long time running processes, batch series of experiments were conducted using contact periods up to 9 days. The results show that the thin films maintained their photocatalytic properties confirming their stability and viability for up-scaling.