Combination of Fe(II)-induced oxygen deficiency and metal doping strategy for construction of high efficiency water oxidation electrocatalysts under industrial-scale current density

Abundant oxygen-vacancy and heteroatomic doping have been demonstrated to be beneficial to obtain high electrocatalytic performance for the oxygen evolution reaction (OER). In present work, a simple cathodic electrodeposition (CED) method based on Fe(II)-induced oxygen deficiency-metal doping ((FeIOD)-I-II/MD) strategy was developed to prepare robust water oxidation electrocatalysts. By using Fe2+ ions as the iron precursors, a series of Ni-doped beta-FeOOH (Ni/beta-FeOOH-x) on the carbon cloth (Ni/beta-FeOOH-x/CC, here, the x is the molar percent of Fe2+ in the total ferric salt; x = 0, 0.2, 0.5, 0.8 or 1) electrocatalysts with different oxygen vacancy content were prepared. Relevant characterizations indicated that the oxygen-vacancy ratio and electrocatalytic OER performances of Ni/beta-FeOOH-1/CC electrocatalysts prepared by using Fe2+ ions as the iron precursor is significantly higher than that of Fe3+. Fascinatingly, the Ni/beta-FeOOH-1/CC with massive oxygen vacancies shows an ultralow overpotential of 192 mV at the current density of 10 mA.cm(-2). Furthermore, the Ni/beta-FeOOH-1/CC catalyst can also be directly driven by a dry cell or solar cell. More importantly, the Ni/beta-FeOOH-1/CC catalyst prepared by CED method based on this (FeIOD)-I-II/MD strategy can realize water oxidation at the industrial current density, and it shows a potential industrial application value in the future.