Manganese‐Doped Hollow Layered Double (Ni, Co) Hydroxide Microcuboids as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

The development of low‐cost, efficient, noble‐metal‐free electrocatalysts for the oxygen evolution reaction (OER) is important for renewable energy conversion. We prepared hierarchical hollow NiCoMn‐layered double hydroxide (LDH) microcuboids that consisted of two dimensional (2D) nanosheets by using a solvothermal method. The prepared Ni 6 Co 11 Mn‐LDH exhibits high OER activity, with an overpotential of 248 mV at a current density of 10 mA cm −2 and a small Tafel slope of 72.2 mV dec −1 , which is even better than the noble‐metal RuO 2 catalyst. It remains stable after chronopotentiometric testing at a high current density of 100 mA cm −2 for 22 h, indicating potential for practical application. The enhanced OER performance is ascribed to the transition of Ni 2+ to Ni 3+ in NiCo‐LDH induced by Mn doping, which activates the Ni sites. This work provides an approach to further optimize the OER performance of NiCo‐LDH based catalysts.