Construction of a MnCo2O4@NiyMx (S and P) crosslinked network for efficient electrocatalytic water splitting†
The preparation of stable, efficient and cost-effective electrocatalysts is a very good strategy for the production of hydrogen and oxygen by water splitting. A precursor material based on MnCo is directly grown on 3-dimensional hollow nickel foam through a simple hydrothermal synthesis method. The MnCo oxide presents a flake-like graded material with controllable morphology by varying the reaction time. Combined with the good catalytic performance of Ni3S2, the two components MnCo2O4 and Ni3S2 can produce synergistic effects in the water splitting process and improve the activity of the electrocatalysts. MnCo2O4@Ni3S2 presents superior catalytic activity and in order to achieve a current density of 40 mA cm−2, an external voltage of 200 mV is required in 1 M KOH solution for the oxygen evolution reaction (OER) test. For the hydrogen evolution reaction (HER) test, an external voltage of only 110 mV is required in order to achieve a current density of 10 mA cm−2. MnCo2O4@Ni3S2 is used as a fully hydrolyzed cathode and anode, and a cell voltage of 1.60 V is required in order to achieve a current density of 10 mA cm−2 in an alkaline medium. Moreover, the material also exhibits good electrochemical stability; it does not decay when the current density is maintained for 15 h.