A cyclopentadienyl rhodium catalyst derivatized with pyrene was used to study the effects of a reduced graphene oxide (rGO) on visible light-driven photocatalytic hydrogen production using formate and Pt nanoparticles. The pyrene-derivatized rhodium catalyst was immobilized on rGO by pi-pi stacking interactions. A tight formation of the Rh catalyst on rGO surprisingly enhanced the hydrogen production upon visible light irradiation, in contrast with the results using a thin formation of the catalyst or the unfunctionalized Rh catalyst. Our results also demonstrated that the catalytic stability of the pyrene-functionalized Rh complex dramatically increased when it was immobilized on rGO during the photocatalytic reaction cycle. RGO played a crucial role in efficiently transferring electrons from the Rh(III)-hydrides to the platinum nanoparticles. (C) 2015 Elsevier Ltd. All rights reserved.