Water oxidation electrocatalysis with iron oxide nanoparticles prepared via laser ablation

Iron oxide nanoparticles (FeO x NPs, 5–30 nm size) prepared via laser ablation in liquid were supported onto Indium Tin Oxide conductive glass slides by magnetophoretic deposition (MD) technique. The re- sulting FeO x @ITO electrodes are characterized by a low amount of iron coverage of 16–50 nmol/cm 2 , and show electrocatalytic activity towards water oxidation in neutral phosphate buffer pH 7 with 0.58 V overpotential and quantitative Faradaic efficiency towards oxygen production. XPS analysis on the oxy- gen region of the FeO x films reveals a substantial hydration of the surface after catalysis, recognized as a crucial step to access reactivity.