One-pot synthesis of Mn2P-Mn2O3 heterogeneous nanoparticles in a P, N -doped three-dimensional porous carbon framework as a highly efficient bifunctional electrocatalyst for overall water splitting

Robust, inexpensive, efficient catalysts for overall water splitting are of significant interest as we look towards the Hydrogen Economy. Herein, we have prepared novel Mn2P-Mn2O3 heterogeneous nanoparticles hosted in a P, N-doped three-dimensional porous carbon framework. Of these, Mn2P-Mn2O3/PNCF displayed ultrahigh stability as a bifunctional electrocatalyst for efficient hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) in alkaline electrolytes. These properties are a result of the abundant heterogeneous interfaces, optimized electronic configurations and hierarchical pore structure of the Mn2P-Mn2O3/PNCF catalyst. This material has a closed zero calculated Gibbs free energy for adsorbed H of −0.013 eV, and can achieve current densities of 10 mA cm−2 and 100 mA cm−2 for HERs and OERs, respectively, whilst requiring only low overpotentials of 98 mV and 330 mV, respectively. In addition, an alkaline electrolyzer with Mn2P-Mn2O3/PNCF as both the anode and cathode demonstrates a nearly comparable activity and higher stability than the present state‐of‐the‐art, Pt/C || RuO2/C, for full water splitting. Mn2P-Mn2O3/PNCF shows great potential for the economical, large-scale production of H2.