Selective growth of graphdiyne-based vanadium–iridium oxide interfaces for efficient alkaline oxygen evolution reaction

Abstract

Electrocatalytic water splitting is a green and sustainable solution for hydrogen production, but its overall performance is still limited by the sluggish and inefficient oxygen evolution reaction (OER). Here, we report the controlled growth of vanadium–iridium oxides (VIrO_x) on the surface of graphdiyne (GDY) to generate well-defined interfaces between GDY and VIrO_x. The scanning electron microscopy and high-resolution transmission electron microscopy images showed the successful growth and uniform distribution of VIrO_x quantum dots on the surface of the GDY nanosheets. The X-ray photoelectron spectra revealed that efficient charge transfer occurred at the interfaces between GDY and VIrO_x quantum dots and led to the formation of mixed-valence metal species. These catalyst advantages notably increased the number of active sites and improved the overall intrinsic activity of the system, resulting in excellent electrocatalytic OER performance with a low overpotential of 121 mV at 10 mA cm⁻², high turnover frequency of 0.914 s⁻¹ at 300 mV, and long-term stability (100 h at 100 mA cm^–2) in alkaline electrolytes.