Ni_1-xCo_xSe nanostructures deposited on nickel foam by a facile potentiostatic route for enhanced OER performance

Ni1-xCoxSe nanostructures with various Ni2+/Co2+ molar ratios were successfully electrodeposited on Ni foam (NF) by a facile potentiostatic route in air at room temperature. Electmdeposition process was carried out at the deposition potential of -0.46 V (vs. SCE) for 1 h. The phase and composition of the deposited product were characterized by X-ray powder diffraction, Field emission scanning electron microscopy, Transmission electron microscopy, EDS mapping, X-ray photoelectron spectroscopy and inductively coupled plasma mass spectrometry. Electrochemical tests showed that Ni0.26Co0.74Se exhibited the best OER performance among all electrodeposited products. To drive the current density of 50 mA cm(-2), the overpotential of 302 mV was required. After continuously catalyzing the OER for 20 h at the current density of 20 mA cm(-2) in 1.0 M KOH solution, the potential only slightly changed from 1.498 to 1.512 V (vs. RHE). Also, after 20000 cycles the overpotential of the Ni0.26Co0.74Se/NF electrode had no obvious decrease, indicating its excellent cycle stability.