Efficient visible light photocatalytic NO abatement over SrSn(OH)6 nanowires loaded with Ag/Ag2O cocatalyst.

SrSn(OH) 6 (SSOH) possesses a high oxidation potential in the valence band (VB), which is suitable for photocatalytic oxidation removal of pollutants. However, the electrons in the VB of these catalysts are difficult to transition to the conduction band (CB) under visible light, which makes it difficult to utilize sunlight effectively. In this work, Ag/Ag 2 O is loaded on the surface of SSOH nanowires, which stimulates the interfacial charge-transfer transition on SSOH. Compared with pure-phase SSOH, the NO abatement ratio of Ag/Ag 2 O-SSOH under visible light irradiation is increased to 45.10%. The e− in the VB of Ag 2 O are excited into the CB under visible light, and are further transferred to the Ag to react with O 2 to produce superoxide radicals. The photo-excited e− in the VB of SSOH enter into the VB of Ag 2 O through interfacial charge-transfer transition to recombine with the photo-generated holes in the VB of Ag 2 O, thereby leaving photo-generated holes in the VB of SSOH. The holes in the VB of SSOH have sufficient oxidizing ability to oxidize the adsorbed hydroxyl groups into hydroxyl radicals. This work provides a new perspective for photocatalytic removal of pollutants by wide band gap photocatalyst under visible light. [Display omitted] • Ag/Ag 2 O cocatalyst/SrSn(OH)6 nanowires are firstly fabricated. • The Ag/Ag 2 O cocatalyst/SrSn(OH) 6 showed high visible light photocatalytic activity. • The mechanism of photocatalytic NO oxidation is revealed using in situ DRIFTS. • The enhanced photocatalysis is ascribed to the interfacial charge-transfer transition. • The detailed process of the interfacial charge-transfer transition is revealed. [ABSTRACT FROM AUTHOR]