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

Abstract

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.