Manganese-decorated CoP@CoFe2O4 nanorod arrays for high-efficiency alkaline water oxidation

Regulating the intrinsic activity of electrocatalysts is an effective strategy towards outstanding behaviour for oxygen evolution reaction (OER). Herein, the rational design of a Mn-CoP@CoFe2O4 core-shell heterojunction using nickel foam (NF) as a supporting material with special interface engineering has been investigated by a facile hydrothermal technique combined with phosphorization and electrodeposition method. The physical characterization demonstrates Mn-CoP@CoFe2O4 core-shell heterostructure with Mn-CoP nanoneedles as core and CoFe2O4 nanosheets as shell has been successfully acquired. The electrochemical measurements of the asprepared Mn-CoP@CoFe2O4/NF core-shell heterojunction nanoarray electrode exhibit the superior electrocatalytic behaviour for OER (Tafel slope of 35.6 mV dec-1 and overpotential of 209.6 mV@10 mA cm-2). The remarkable OER behaviour may be ascribed to the sufficient active sites and the enhanced intrinsic activity due to the introduction of CoFe2O4 and Mn element, which can regulate the electron structure and increase the turnover frequency. Furthermore, the Mn-CoP@CoFe2O4/NF electrode appears an excellent long-run stability during the OER process at 100 mA cm-2 for 100 h. Therefore, the construction of metal doping transition metalbased core-shell heterostructure electrocatalysts may be a promising way for the remarkable OER electrocatalytic performance towards water splitting.