Hydrangea flower-like nanostructure of dysprosium-doped Fe-MOF for highly efficient oxygen evolution reaction

Developing catalysts with high intrinsic activity toward oxygen evolution reaction (OER) has paramount importance to meet the ever-increasing quest for sustainability demands for green energy solutions but challenging. Herein, a one-step synthesized hydrangea flower-like metal-organic framework (MOF) by dysprosium (Dy)-doped Fe-MOF is reported (Dy0.05Fe-MOF/NF). Impressively, the obtained electrocatalyst possesses optimal OER intrinsic activity, showing a low overpotential of 258 mV at 100 mA·cm−2, superior to the capability of the noble metal RuO2. In addition, an overpotential of 318 mV is needed for Dy0.05Fe-MOF/NF to drive 500 mA·cm−2. The remarkable performance of Dy0.05Fe-MOF/NF can be explained by the surface-active electron density modulation of Fe sites, because the doping of Dy with a lower electronegativity than doping of Fe could donate electrons to the neighboring Fe atoms, resulting in profoundly improved OER performance. Beyond that, this work not only offers a perspective to understand the OER mechanism of rare earth doping, but also guides us to design more ideal electrocatalyst and beyond.