Highly active Ag clusters stabilized on TiO2 nanocrystals for catalytic reduction of p-nitrophenol

Ag/TiO 2 nanocomposites comprising of Ag clusters on TiO 2 nanocrystal surfaces are of great significance in catalysts and advanced functional materials. Herein a novel method to synthesize Ag/TiO 2 nanocomposites with Ag clusters under 2   nm on TiO 2 nanocrystal surfaces have been developed. The success of this method relies on a silver mirror reaction in toluene, which refers to the reduction of silver-dodecylamine complexes by acetaldehyde in the presence of mono-dispersed TiO 2 nanocrystals. The prepared Ag/TiO 2 nanocomposites have been characterized by FT-IR spectra, UV–vis absorption spectra, X-ray diffraction (XRD) analysis, ultra high resolution scanning electron microscope (Ultra-HRSEM), high resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectra (XPS). Catalytic activity of Ag/TiO 2 nanocomposites is evaluated for the reduction of p -nitrophenol (4-NP) into p -aminophenol (4-AP) by NaBH 4 . Results demonstrate that Ag/TiO 2 nanocomposites have shown an outstanding catalytic activity as well as a good stability in successive reduction of 4-NP. Noticeably, TOF of Ag/TiO 2 -0.75 nanocomposites obtained in this work is the highest among Ag based catalysts previously reported.