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

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 (0.3–1 at.%). 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.

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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.