Au Nanoparticles Loaded Bi₅Ti₃FeO₁₅ Ferroelectric Nanosheets with Enhanced Photocatalytic Activity for NO Removal

Bi₅Ti₃FeO₁₅ ferroelectric nanosheets are synthesized by molten salt method and further decorated Au nanoparticles on the surface of nanosheets by chemical reduced method. The phase structure, morphology, and optical properties of the samples are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy, respectively. The introducing Au nanoparticles in Bi₅Ti₃FeO₁₅ photocatalyst significantly improved light absorption and inhibit recombination of photo-generated electron/hole pairs due to the typical LSPR effect and the interface effect. The Au/Bi₅Ti₃FeO₁₅ composite photocatalyst exhibited superior photocatalyst activities for NO removal and excellent stability photocatalyst performance compared with the Bi₅Ti₃FeO₁₅. The results of Density functional theory (DFT) confirm that the formation of ohmic contact between Bi₅Ti₃FeO₁₅ and Au, which improve the ability of electron transfer and oxygen activation. Thus, the efficiency of separation of photo-induced e ⁻/h ⁺ pairs and the generation of ⋅O₂⁻ and ⋅OH species are promoted. The scavenger experiments measurements reveal that e ⁻ play the most critical role, h ⁺ and ·OH serve as a secondary active species in the photocatalytic activity for NO removal. Furthermore, the NO removal reaction process on the surface of the Au/Bi₅Ti₃FeO₁₅ photocatalyst is studied by in-situ FTIR spectroscopy. This research provides a feasible idea to construct photocatalyst with high efficiency activity via decorating noble metal on ferroelectric materials. Graphical Abstract: [Figure not available: see fulltext.]