Well‐Monodispersed Iron‐Doped InOOH Nanoparticles with Enhanced Activity for Oxygen Evolution

Abstract Designing efficient and stable catalysts with smaller‐sized nanostructures holds promise in alkaline water electrolysis, especially for the oxygen evolution reaction (OER), whereas selecting proper candidates and facile synthetic strategies remain challenging. Herein, well‐monodispersed InOOH nanoparticles (NPs) tailored by Fe doping with diameters of about 7 nm are synthesized by using a two‐phase colloidal method and secondary solvothermal process. Benefiting from the large electrochemically active surface area given by the unique monodispersed NP morphology, the increased active sites generated by tunable Fe doping that can increase the OER activity of the host oxide, and the synergistic effect between In and Fe, Fe‐doped InOOH NPs exhibits superior electrocatalytic activity toward the OER. As a result, well‐monodispersed Fe‐doped InOOH NPs could achieve current densities of 10 and 100 mA cm −2 at overpotentials of 220 mV and 266 mV, respectively, in alkaline media (1.0 M KOH), and possess an excellent catalytic durability of 27 hours, transcending most of the previously reported Fe‐rich OER electrocatalysts.