Pt/TiO2 Coupled with Water-Splitting Catalyst for Organic Pollutant Photodegradation: Insight into the Primary Reaction Mechanism.

A composited system was fabricated by coupling Pt/TiO2 with water-splitting catalyst for photooxidation of organic pollutants in aqueous solutions. The new composited system exhibits more efficient photocatalytic activity than pure Pt/TiO2 does under UV light irradiation. The promoting effect is dependent on the photo-produced H2 over the composited system. The active oxygen species, hydroxyl radical (·OH) and hydrogen peroxide (H2O2), are measured by fluorescence spectroscopy and photometric method, respectively. The results reveal that the produced H2 by photocatalytic water splitting over NiO/NaTaO3:La transfers to Pt particle of TiO2 surface, then reacts with introducing O2 to generate in situ intermediate H2O2, and finally translates into ·OH radical to accelerate the photooxidation of organic pollutants. [ABSTRACT FROM AUTHOR]