Ir Nanoparticles Supported on Oxygen-Deficient Vanadium Oxides Prepared by a Polyoxovanadate Precursor for Enhanced Electrocatalytic Hydrogen Evolution.

Developing highly active electrocatalysts is crucial for the application of electrocatalytic water splitting. In this study, we prepared vanadium oxide-graphene carbon nanocomposites (VO/C) with abundant defects using a carbon- and oxygen-rich hexavanadate derivative Na[VO{(OCH)CCH}] as a precursor without the addition of an extra carbon source. Subsequently, the VO/C was used as a catalyst support to load a small amount of Ir, forming the Ir/VO/C nanoelectrocatalyst. This catalyst exhibited low hydrogen evolution overpotentials of only 18.90 and 13.46 mV at a working current density of 10 mA cm in 1.0 M KOH and 0.5 M HSO electrolyte systems, outperforming the commercial Pt/C catalysts. Additionally, the catalyst showed excellent chemical stability and long-term durability. This work provides a new strategy for the design and synthesis of highly active electrocatalysts for water splitting.