Photocatalytic NH<sub>3</sub> Splitting on TiO<sub>2</sub> Particles Decorated with Pt–Au Bimetallic Alloy Nanoparticles
Yasuhiro Shiraishi, Shota Toi, Satoshi Ichikawa, Takayuki Hirai
Abstract
Photocatalytic splitting of aqueous NH3 into H2 and N2 on semiconductor powders is an important reaction toward on-site production of H2 from NH3, a promising hydrogen carrier for sustainable energy society. Earlier reports revealed that TiO2 loaded with Pt nanoparticles (Pt/TiO2) is the most effective catalyst for this reaction. Herein, we report that TiO2 loaded with homogeneously mixed bimetallic alloy nanoparticles containing 90 mol % Pt and 10 mol % Au (Pt0.9Au0.1/TiO2) promotes photocatalytic NH3 splitting very efficiently. Electrochemical analysis indicates that Au alloying to Pt lowers the height of Schottky barrier created at the metal/TiO2 interface. This promotes efficient transfer of conduction band electrons on TiO2 to metal particles. This results in enhanced separation of the photogenerated charges, thus promoting efficient NH3 splitting.