Photochemical hydrogen evolution using Sn-porphyrin as photosensitizer and a series of Cobaloximes as catalysts

Herein, we report a photochemical hydrogen evolution system consisting of various cobalt based catalysts, a metallated Sn porphyrin as photosensitizer and a triethanolamine as a sacrificial electron donor in acetonitrile/H2O (1:1) solution. Since a tin metallated porphyrin is used for the first time as photosensitizer in this type of systems, a systematic study was performed in order to elucidate the best conditions for H-2 production. Upon visible irradiation hydrogen production was detected with the best result obtained at pH 7 with a TON of 150, after 100 h in the presence of catalyst 1. Moreover, when TiO2 nanoparticles were added at the catalytic system 2 hydrogen production was increased from 53 TON to 131 TON, under the same experimental conditions.