Enhancing the water splitting performance of a reduced graphene oxide–platinum nanoparticle hybrid using an intercalating ethylenediamine polar space group

Abstract

We found that the water-splitting performance of platinum-doped rGO (rGO-Pt) can be significantly enhanced by intercalating ethylenediamine (EDA). The coexistence of proton conductivity (PrC) and electron conductivity (EtC) in the as-prepared rGO-Pt-EDA facilitated this enhancement. The well-known electron insulator graphene oxide (GO) gains EtC when reduced to rGO or doped by metal. In contrast, proton conductive GO loses PrC due to its reduction or metal doping. Herein, we found that such elusive PrC could be regained in electron conductive rGO-Pt when EDA is intercalated. rGO and Pt support EtC, whereas hydrophilic EDA molecules support PrC through improved hydration dynamics. The intercalation of EDA resulted in the shrinking of the band gap and increase in the surface area. All these factors afforded the composite to display the rare coexistence of proton and electron conductivity, with respective PrC and EtC values as 2.4 × 10⁻⁵ S cm⁻¹ (at 313 K and 80% relative humidity) and 9 μA (at ±1 V). Due to the existence of this dual conductivity, the materials could achieve excellent photocatalytic hydrogen generation performance at 31.09 μmol g⁻¹ h⁻¹, which indeed is much higher than that of rGO-Pt (7.48 μmol g⁻¹ h⁻¹) or rGO-EDA (9.38 μmol g⁻¹ h⁻¹).