Nickel Foam Supported Co₃O₄@Ni₃Se₄ Core‐Shell Nanorod Arrays with Long‐Term and Efficient Catalytic Performance for Water Splitting

Abstract Exploitation of the efficient and highly stable catalytic performance provided by bi‐functional catalysts is important for practical water splitting. Herein, Co₃O₄@Ni₃Se₄ core‐shell nanorod arrays on nickel foam (Co₃O₄@Ni₃Se₄/NF) are successfully synthesized as long‐term and efficient bi‐functional catalysts for water splitting in 1.0 M KOH. The satisfactory Co₃O₄@Ni₃Se₄/NF catalyst exhibits excellent activity with low overpotentials of 260 mV and 180 mV at 10 mA cm⁻² for OER and HER, respectively. In addition, its overpotential is only higher than the initial overpotential within 10 mV when the Co₃O₄@Ni₃Se₄/NF has been used after 30 hours at OER and HER. Significantly, the cell based on bi‐functional Co₃O₄@Ni₃Se₄/NF||Co₃O₄@Ni₃Se₄/NF couple shows a low potential of 1.735 V at 10 mA cm⁻² in alkaline electrolyte and remains a current density of 10 mA cm⁻² for 30 hours without serious attenuation, indicating that the as‐prepared catalyst has huge potential in practical water splitting.