Visible-Light-Driven Photocatalytic Performance of Ag@TiO₂ Nanocrystals: The Effects of Phases and Morphologies

Abstract:

Silver decorated TiO₂ nanoparticles (Ag@syn-TiO₂, Ag@P25) were synthesized by photoreducing Ag⁺ species in the presence of the synthetized TiO₂ (syn-TiO₂) nanocrystals or P25. The samples obtained were characterized by XRD, XPS, UV-vis and TEM. The XRD results showed the syn-TiO₂ nanoparticles were pure anatase, and the P25 nanoparticles were the mixture of antase and rutile. The TEM observations and XPS spectra indicated that Ag species anchored on the surfaces of syn-TiO₂ nanoparticles as Ag⁰ and AgO nanoclusters (NCs). The Ag NCs have a size range of 13 nm and the AgO NCs have a size range of 1015 nm. The Ag NCs on the surface of P25 have a size range of 57 nm, and no AgO species were found. The photocatalytic performance of the Ag@syn-TiO₂ and Ag@P25 samples was evaluated by degradating Rhodamine B (RhB) under visible-light irradiation (λ ≥ 420 nm). The results indicated that the phases and morphologies of TiO₂ nanocrystals have effects on their photocatalytic properties, and that the syn-TiO₂ nanocrystals wiht the pure anatase are more active than P25 with the mixture of antase and rutile in RhB degradation. The possible mechanisms were discussed.

• Periodical: Key Engineering Materials (Volumes 602-603)
• Pages: 1043-1047
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.602-603.1043
• Online since: March 2014
• Authors: Qian Qian Chen, De Liang Chen*, Lian Fang Ge, Shao Ke Hou, Rui Zhang
• Keywords: Ag Nanoparticle, Photodegradation of Rhodamine B, Plasmonic Photocatalysts, TiO₂

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