Amorphous Iridium Oxide Nanoparticle Films Prepared by Low-temperature Annealing and Plasma Treatment as Highly Efficient Oxygen Evolution Electrocatalysts

This study reports a facile strategy to prepare IrOx nanoparticle films on FTO substrates through simple spin-coating, annealing, and plasma treatment, which act as efficient electrocatalysts towards oxygen evolution reaction (OER). Typical amorphous IrOx nanoparticle film obtained by annealing at 300 °C and air-plasma treatment exhibits excellent OER performance in acidic electrolyte with a low overpotential of 290 mV at 10 mA cm−2, a Tafel slope of 55.4 mV dec−1, and an ultrahigh mass activity of 993 A g−1 at 1.55 V, which is among the best compared to the results reported in the literature.