FeNi co-doped MnO2 nanosheet arrays enable efficient water splitting performance
摘要
Developing efficient and stable bifunctional electrocatalysts is key to achieving renewable energy-driven water splitting. Herein, bimetallic-doped δ MnO2 (FeNi-δ MnO2) was prepared by hydrothermal and self-assembly methods. FeNi-δ MnO₂ exhibits excellent alkaline water redox performance, with an overpotential of 260 mV for oxygen evolution reaction (OER) and 186 mV for hydrogen evolution reaction (HER) at a current density of 10 mA cm⁻2. In addition, the long-term stability of the FeNi-δ MnO2 catalyst for OER and HER is maintained for 50 and 60 h, respectively, at a current density of 500 mA cm⁻2. The nanosheet array morphology was preserved after FeNi co-doping, indicating that the doping process did not compromise structural integrity and effectively exposed active sites, thereby enhancing catalytic activity. In addition, introducing Fe3⁺ leads to adjusting the Mn3⁺/Mn4⁺ ratio, enhancing the electronic conductivity. FeNi-δ MnO2 was used as cathode and anode for water electrolysis, and the cell voltage was 1.67 V at a current density of 10 mA cm−2. This work provides a new strategy for designing low-cost, high-performance bifunctional electrocatalysts.