Heteroatoms Adjusting Amorphous FeMn-Based Nanosheets via a Facile Electrodeposition Method for Full Water Splitting

There still exists a resplendent prospect of developing a robust and stable non-noble metal catalyst for overall water splitting. Herein, we designed highly efficient amorphous FeMn-based electrocatalysts toward oxygen/hydrogen evolution reactions (OER/HER) via a simple electrodeposition method using Ni foam (NF) as the support. Nonmetal heteroatoms are introduced to adjust the intrinsic properties through this route without any post-treatment steps. Benefiting from the synergistic effect of Fe and Mn species and nonmetal atoms, in 1.0 M KOH solutions, FeMnO_x efficiently drives the OER with an overpotential of 220 mV at 10 mA cm^–2, and P-FeMnO_x is helpful for both the OER and the HER (251 and 97 mV @ 10 mA cm^–2) catalysis. Two electrolytic tanks employing P-FeMnO_x as a cathode and FeMnO_x/P-FeMnO_x as anodes show low voltages reaching 50 mA cm^–2 (1.62 and 1.68 V). This work highlights the combination of advantages between nonmetal and different non-noble metal elements in high-performing overall water electrocatalysis.