Effect of deposition of silver on structural characteristics and photoactivity of TiO2-based photocatalysts

• Published in: Applied catalysis. B, Environmental Vol. 127; pp. 112 - 120
• Main Authors: PULIDO MELIAN, E, GONZALEZ DIAZ, O, RODRIGUEZ, J. M. Doña, COLON, G, NAVIO, J. A, MACIAS, M, PENA, J. Perez
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 30-10-2012; Elsevier
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Impregnation; Phenol; Photocatalysis; Photochemistry; Photodeposition; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Silver; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TiO2; Silver; Impregnation; Photodeposition; Phenol; Photocatalysis; TiO2; Binary compound; Nanoparticle; Alcohol; X ray; Photocatalyst; Characterization; Particle; Noble metal; Photoelectron spectrometry; TiO; Deposition; Photochemical degradation; Scanning electron microscopy; BET method; Reference; Transition element compounds; Transition metal; X ray diffraction; Heterogeneous catalysis; Liquid; Pollutant; Transmission electron microscopy; Phenols; Benzenic compound; Models; Titanium oxide; Reflectance; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2012.08.007

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► A highly photoactive homemade photocatalyst was modified by silver deposits. ► The liquid impregnation method resulted in photocatalysts with higher activity. ► Photoactivity of 0.3Ag-iTiO2 was higher than that of P25 for several pollutants. ► Its efficiency decreases only slightly after the first use. ► 0.3Ag-iTiO2 sediments quickly and so, its reutilization would be possible.
The homemade bare TiO2 photocatalyst obtained in a previous work was modified with nanosized silver particles by liquid impregnation and photodeposition methods to obtain different noble metal loadings (0.3–1at.%). Characterization of the synthesized photocatalysts was carried out by the BET method, XPS, TEM, SEM-EDX, XRD and diffuse reflectance measurements. Photocatalytic activity of these silver-deposited TiO2 nanoparticles was tested by photocatalytic degradation of phenol as a reference model representing phenolic pollutants. The noble metal content on the TiO2 surface affected the efficiency of the photocatalytic process, and the photocatalytic activity of noble metal-modified TiO2 was considerably better than that of bare TiO2. Phenol decomposition rate was higher with TiO2 modified by the liquid impregnation method than with TiO2 modified by the photodeposition method.