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 Ni6Co11Mn‐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 RuO2 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 Ni2+ to Ni3+ 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. Practical solution: Manganese‐doped NiCo‐based layered double hydroxide (LDH) is used as an efficient catalyst for the oxygen evolution reaction, which exhibits 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. In addition, it can operate stably for 22 h at a current density of 100 mA cm−2, which shows potential for practical application. The improved performance is ascribed to the transition of Ni2+ to Ni3+ due to Mn doping.