Boron-doped graphene as electrocatalytic support for iridium oxide for oxygen evolution reaction

The present work details the development of IrO2 nanoparticles (nps) supported on B-doped reduced graphene oxide as an oxygen evolution reaction (OER) electrocatalyst for electrochemical water splitting. IrO2 on boron-doped reduced graphene oxide (B-rGO) is synthesized via sequential steps of pyrolysis to prepare B-rGO and a hydrothermal method for modification of B-rGO with IrO2 nps. With 2 wt% boron doping in graphene, a 0.10 V decrease in the OER onset potential is observed for IrO2 catalysts on B-rGO (IrO2-B-rGO). The Tafel slope for the OER on B-rGO is estimated to be 124.8 mV dec(-1), which is lower than that on IrO2-rGO and suggests strong adsorption of intermediates such as OH on the IrO2 surface by the B-doping of graphene in acidic solution. In this article, we demonstrate the effect of boron doping on the electronic structure modification of the IrO2 nps, which is expected to generate more electrocatalytic centers and enhance the catalytic activity.