In-situ photo-reduction of silver particles and their SPR effect in enhancing the photocatalytic water splitting of Ag2O/TiO2 photocatalysts under solar light irradiation: A case study

Plasmonic Ag2O/TiO2 photocatalysts were synthesized by impregnating silver oxide nano clusters over the surface of TiO2. It is found that the in-situ photo reduced silver particles showed visible light absorption in a wide range of wavelength 400-800 nm due to localized surface plasmon resonance. The in-situ formed metallic silver transfer electrons to the TiO2 through SPR excitation and thus improving photocatalytic hydrogen production. The SPR behavior of silver particles on TiO2 was characterized by UV-vis diffuse reflectance spectroscopy and the X-ray photoelectron spectroscopy confirms the metallic silver. X-ray diffraction and transmission electron microscopy confirm the crystallinity of the prepared samples. H-2-temperature-programmed reduction, photoluminescence, electron paramagnetic resonance, infrared spectroscopy, BET-surface area and Raman spectra were used to understand the morphological and chemical nature of the catalysts. Among the samples, 1 wt% Ag/TiO2 showed the best activity ca. 23 mmol g(-1) in presence of glycerol scavenger.