Silvered TiO₂ for Facet-Dependent Photocatalytic Denitrification

In this paper, the influence of exposed facets of silvered TiO₂ photocatalysts for photodenitrification was fundamentally investigated. We found that photodeposition of silver on 001-faceted TiO₂ was prone to form Ag/Ag₂O/001-TiO₂ triple junctions. Comparatively, oxygen vacancies in 101-faceted TiO₂ alleviated the oxidation rate, which contributed to the formation of a junctioned interface between TiO₂ and metallic Ag⁰. Benefiting from the Z-scheme charge transfer pathway mediated by adjacent Ag, the nitrate reduction rate and N₂ selectivity for Ag₂O/Ag/101-TiO₂ reached 99.1 and 81.1%, respectively, which were much higher than those of silvered 001-TiO₂ and P25. In this work, we prepared TiO₂-based photocatalysts with specific exposed crystal facets and good crystallinity at the heterogeneous interface for denitrification applications.