Iron Alcoholate‐Derived FeOOH Nanoflowers Enabling Lattice Oxygen‐Mediated Oxygen Evolution

ABSTRACT

Although metal alcoholates have certain applications in the research of oxygen evolution reaction (OER) catalysts, they still have problems of low stability and activity, which restrict their development. To address these issues, this work regulates the ratio of iron‐based metal alcoholate ligands by the hydrothermal method and constructs nanoflower‐like nanostructures with crystalline and amorphous coupling through etching, thereby improving the catalytic activity. Among them, Fe‐gly‐1.5 demonstrates exceptional catalytic performance under high current density, evidenced by a 243 mV overpotential (100 mA cm ⁻² ) and 200 h stability (250 mA cm ⁻² ). Moreover, the two‐electrode alkaline water electrolyzer assembled with Fe‐gly‐1.5 and Pt/C catalysts shows sustainable stability in the overall water splitting process. Electrochemical studies using probe molecules such as TMAOH and methanol demonstrate that the mixed‑ligand system exhibits unique advantages in catalytic reactions. Further investigations through in situ Raman and Fourier transform infrared (FTIR) spectroscopy, combined with differential electrochemical mass spectrometry (DEMS), reveal that the active phase of Fe‐gly‐1.5 is δ/β‐FeOOH formed via reconstruction during the OER process, and confirm that its reaction pathway follows the lattice oxygen‐mediated mechanism (LOM).