Reasons for the deactivation of Pt/TiO2 photocatalyst treated by inert gas N2

The effect of N₂ treatment on the photocatalytic activity of Pt⁰/TiO₂ was investigated. The results showed that after treatment at 500 °C in N₂, 70% of the photocatalytic activity of 1.0 wt.% Pt⁰/TiO₂ was lost by the evaluation of photocatalytic oxidation reaction of C₃H₆. Transmission electron microscopy (TEM) and Ar⁺ ion sputtering tests revealed that in the course of high-temperature N₂ treatment, the size of Pt⁰ particles on TiO₂ increases and a strong interaction between metal and support, i.e. Pt⁰ particles encapsulated by Ti_xO_y, happens, which are the reasons for the deactivation of Pt⁰/TiO₂ photocatalyst treated by high-temperature N₂.