(610a) Pt/TiO2 Nano-Catalyst Synthesized by Atomic Layer Deposition
Pt metal was deposited on TiO2 P-25 photocatalyst nanoparticles by the atomic layer deposition (ALD) method to increase TiO2 photocatalytic activity. Methylcyclopentadienyl-(trimethyl) Platinum(IV) (MeCpPtMe3) and oxygen were used as precursors to deposit Pt at temperatures between 150°C-400°C. The mechanism of Pt ALD deposition was studied through mass spectrometry. The effects of deposition temperature on the Pt doping as well as on the TiO2 photoactivity were explored. The lower temperature limit for Pt ALD is 200°C; although the MeCpPtMe3 chemisorption on the substrate particles occurred at 150°C as well, while the ligands of absorbed Pt precursor were barely oxidized during the O2 dose period when the temperature was less than 200°C. Pt doping via ALD resulted in a significant improvement in TiO2 photoactivity. The operating temperature and number of ALD cycles have been optimized to maximize Pt surface dispersion and the photoactivity of TiO2 nanoparticles.