Nanostructured IrO x supported on N-doped TiO 2 as an efficient electrocatalyst towards acidic oxygen evolution reaction.

Reducing the Ir consumption without compromising the catalytic performance for the oxygen evolution reaction (OER) is highly paramount to promote the extensive development of the environmentally-friendly solid polymer electrolyte water electrolysis (SPEWE) system. Herein, TiO 2 is doped with N through facile NH 3 gas treatment and innovatively employed to support IrO x nanoparticles towards acidic OER. N-doping action not only dramatically boosts the electrical conductivity and dispersing/anchoring effects of TiO 2 , but also effectively improves the electron-transfer procedure. As a result, the IrO x /N-TiO 2 electrocatalyst exhibits prominent catalyst utilization, catalytic activity and stability. Specifically, the overpotential required to deliver 10 mA cm -2 is only 270 mV, and the mass activity climbs to 278.7 A g Ir -1 @ 1.55 V RHE . Moreover, the single cell voltage is only 1.761 V @ 2.0 A cm -2 when adopting IrO x /N-TiO 2 as the anode catalyst, which is 44 mV lower than that of the commercial IrO 2 counterpart.