Roles of Crystal Surface in Pt-Loaded Titania for Photocatalytic Conversion of Organic Pollutants: A First-Principle Theoretical Calculation

Titania modified with nanosized metallic clusters is found to substantially enhance its photocatalytic capacity for renewable energy generation and environmental purification, but the underlying mechanism, especially the roles of crystal surface in noble-metal-loaded TiO₂, remain unclear. In this work, such roles in the Pt-loaded anatase TiO₂ for the photocatalytic conversion of nitrobenzene (NB), a model pollutant, are explored by first-principle calculations. The theoretical calculations reveal that the Pt-TiO₂ complex has a higher catalytic activity toward NB conversion than pure Pt clusters, and the (001) facets of TiO₂ in this complex tend to accumulate more positively charged holes and thus have a higher photocatalytic activity than the (101) facets. Furthermore, the thermodynamic and kinetic results also show that the Pt cluster loaded on the (001) surface of anatase TiO₂ is favored for NB conversion in the photooxidation pathway. This work deepens our fundamental understanding on the evolution of molecule-photocatalyst interface and provides implications for designing and preparing photocatalysts.