Photoinduced Ethylene Polymerization on Titania Nanoparticles

Herein we report on the ability of H2-photoreduced TiO2 nanoparticles in catalyzing ethylene polymerization without the use of any alkylating agent. Even more, we demonstrate that the same reaction occurs directly on stoichiometric TiO2 in the presence of ethylene under UV-light irradiation at room temperature, thus without any pre-reduction step. The synergic use of electron paramagnetic resonance and diffuse reflectance UV-Vis-NIR spectroscopy allowed us to identify and correlate different Ti3+ EPR signals and UV-Vis-NIR bands; while transmission FT-IR spectroscopy (applied under in situ UV-light irradiation) was fundamental to prove ethylene polymerization and to observe ethylene oxidation by-products. The possibility to easily polymerize ethylene in a one-step procedure can be a promising approach to increase the compatibility of TiO2 as inorganic additive for polyethylene blends.