Photocatalytic hydrogen evolution by iridium(III)-rhodium(III) system: Effect of the free ligand

摘要

Rh(III) complexes of the general form {RhL4Cl2} with pyridine derivatives ligands (L) were used for the first time as water reduction catalysts in photocatalytic hydrogen generation process in pair with [Ir(ppy)(2)bpy](+) complex as a photosynthesizer. The efficiency of given Ir(III)-Rh(III) systems in the photocatalytic hydrogen generation process was found to be on the level of 20-30% which is corresponding to the highest currently achieved quantum efficiency values for homogeneous photocatalysts. Fast deactivation of the systems due to destruction of {RhL4Cl2} units was observed but it was suppressed via addition of extra amount of free L ligand in the reaction mixture. Quantum efficiency of modified in this manner [Ir(ppy)(2)bpy](+)/{RhL4Cl2} systems achieved up to 80% value. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.