(349f) Synthesis and Characterization of Ag-ETS-10@ETS-10 Core-Shell Photocatalyst

Engelhard titanosilicate ETS-10 is a large-pore zeotype material [1] with well-defined monatomic semiconductor ?Ti-O-Ti-O-Ti? chains with a band gap energy of 4.03 eV, making ETS-10 a promising candidate in photocatalytic applications [2]. In order to overcome the narrow absorption range of ETS-10 many groups have investigated post-synthesis modifications, including but not limited to transition metal incorporation [3], to extend the absorption spectra into the visible region. In addition, efforts have been made to hinder the recombination of the photoexcited electron-hole pairs, therefore improving the photocatalytic activity in both UV and visible range. Despite the enhanced photocatalytic activity of Ag-modified ETS-10 (in the visible range) [3, 4], the exposure of the metal and oxide surfaces to the reactants and surrounding medium during photocatalysis becomes problematic. Thus, synthesis of heterostructures with metal cores and semiconductor shells will allow both stability and enhanced photocatalytic activity of the material. Here, the synthesis and characterization of Ag@ETS-10 core-shell photocatalyst are reported. Ag-photodeposited ETS-10 were used as seeds in the preparation of Ag-ETS-10 core-shell morphology from synthesis mixture composition of 4.55 Na₂O : TiO₂: 5.5 SiO₂ : 1.5KF : 300 H₂O. Preliminary photocatalytic experiments will be presented.

[1] S.M. Kuznicki, US Patent 4, 853, 2002 (1989). [2] E. Borello, C. Lamberti, S. Bordiga, A Zecchina, and C. O. Arean, Quantum-size effects in the titanosilicate molecular sieve, Applied Physics Letters, 1997, 71, 2319-2321. [3] S. Uma, S. Rodrigues, I.N. Martyanov, and K.J. Klabunde, Exploration of photocatalytic activities of titanosilicate ETS-10 and transition metal incorporated ETS-10, Microporous and Mesoporous Materials, 67 (2004) 181-187. [4] Z. Ji, D.M. Callahan, E.A. Pandowo, M.N. Ismail, J.Warzywoda, and A.Sacco Jr, Silver modification of titanosilicate ETS-10 for visible light photocatalysis, in preparation.