Co/Fe Selenides Hybrids: Hydrothermal Synthesis from Layered Double Hydroxides Precursor for Highly Efficient Oxygen Evolution Reaction
The transition metal selenides are recognized as ideal substitutes for RuO2 and IrO2 toward oxygen evolution reaction (OER). Herein, a selenides hybrid consisting of Co3Se4 and FeSe2 was prepared successfully by a facile one-step hydrothermal method via CoFe-layered double hydroxides (LDHs) nanosheets as precursor. Electrochemical test on the rotating disk electrode demonstrates that the hybrid possesses good performance for OER during water splitting. The Co3Se4 and FeSe2 catalyst can achieve an overpotential as low as 280 mV at 10 mA cm-2 (close to RuO2) with the Tafel slope of 51 mV dec-1. Such OER activity is also better than majority of as-reported metal selenide catalysts. It could be attributed to the high electrocatalytical activity of Co3Se4 and the synergistic effect between the two metal selenides, which reduce the reaction energy barrier effectively. Long term stability test shows that the sample can last for 24 hours without significant attenuation. Therefore, this work not only provides a facile synthesis method for metal selenides from LDHs precursor, but also supplies an efficient hybrid electrocatalyst as a promising candidate for water oxidation.