Efficient Electrochemical Water Splitting Through Self-Supported Copper Selenide Nanosheets on Cu Foil: Effect of Immersion Time

Transition metal selenides have been attracting enormous attention for electrocatalytic water oxidation. Herein, a self-supported Cu3Se2@Cu electrocatalyst is prepared using the simple self-growth method at different immersion times. The immersion time is critical in the conversion of Cu(OH)(2) to Cu3Se2 as well as the modification of surface morphology. The growth of thin films is analyzed using a field emission scanning electron microscope and X-ray photoelectron spectroscopy techniques. The electrochemical analysis shows that 230 and 351 mV of overpotential are required to reach a current density of 10 and 100 mA cm(-2), respectively, for the oxygen evolution reaction (OER). The chronopotentiometry measurement over 50 h at a current density of 100 mA cm(-2) shows excellent stability of the self-grown electrocatalyst. This work may provide an effective and controlled strategy to convert Cu substrate to Cu3Se2 for efficient OER catalysts with the self-growth method.