Multiphase TiO2 aerogels incorporated with Pd for mixed catalysis in wide UV–Vis spectrum

Abstract

This paper reports the one-pot synthesis and characterization of multiphase TiO2 aerogels incorporated with Pd nanoparticles as photocatalysts for p-nitrophenol reduction. The junction between palladium nanoparticles and titania aerogels resulted in a catalytic duality, due to the photocatalytic properties of titania through in situ hydrogen formation when excited with UV radiation and the catalytic ability of palladium in forming radical hydrogen on its surface, which dispensed with the use of reagents such as NaBH4 in p-nitrophenol reduction reactions. Additionally, the formation of a trap for photogenerated electrons, a high surface area, the presence of the three crystalline phases of titania (anatase, brookite and rutile) and the antenna effect, together with enhanced the electron mobility allowing its transport to the active sites. This resulted in a delay in electron/hole pair recombination and, consequently, promoted high catalytic efficiency in the UV–Vis spectrum.