Consecutive Charging of a Perylene Bisimide Dye by Multistep Low‐Energy Solar‐Light‐Induced Electron Transfer Towards H(2) Evolution

A photocatalytic system containing a perylene bisimide (PBI) dye as a photosensitizer anchored to titanium dioxide (TiO(2)) nanoparticles through carboxyl groups was constructed. Under solar‐light irradiation in the presence of sacrificial triethanolamine (TEOA) in neutral and basic conditions (pH 8.5), a reaction cascade is initiated in which the PBI molecule first absorbs green light, giving the formation of a stable radical anion (PBI(.−)), which in a second step absorbs near‐infrared light, forming a stable PBI dianion (PBI(2−)). Finally, the dianion absorbs red light and injects an electron into the TiO(2) nanoparticle that is coated with platinum co‐catalyst for hydrogen evolution. The hydrogen evolution rates (HERs) are as high as 1216 and 1022 μmol h(−1) g(−1) with simulated sunlight irradiation in neutral and basic conditions, respectively.