Defect Engineering Promoted Ultrafine Ir Nanoparticle Growth and Sr Single‐Atom Adsorption on TiO₂ Nanowires to Achieve High‐Performance Overall Water Splitting in Acidic Media

Abstract This work reports the use of the metal‐support interaction strengthening through defect engineering and single atom adsorption to the supports to increase the catalytic activities of metals. Specifically, the plasma treated TiO₂ nanowires with the Ir nanoparticle growth and the Sr single atom adsorption (the Ir@Sr‐p‐TiO₂ NWs) are synthesized and demonstrated to be efficient catalysts for OER and HER. They only need overpotentials of 250 and 32 mV to drive 10 mA cm⁻² for OER and HER, respectively. Their OER and HER activities are much higher than the commercial IrO₂ and Pt/C. The high activities of the Ir@Sr‐p‐TiO₂ NWs mainly arise from the strengthened metal‐support interactions between the Ir nanoparticles and the p‐TiO₂ NWs, achieved by the plasma generated oxygen defects (Vo·) and the Sr adsorption on the p‐TiO₂ NWs. Analysis and DFT calculations indicate that the Vo· and Sr adsorption can promote the charge transfer from the p‐TiO₂ NWs to the Ir nanoparticles, optimizing the adsorptions of the OER and HER intermediates on the O‐ and H‐covered Ir nanoparticles. Additionally, the strong metal‐support interactions can increase the stabilities of the Ir NPs against the chemical corrosions, increasing the OER and HER durabilities of the Ir@Sr‐p‐TiO₂ NWs.