3D porous network heterostructure NiCe@NiFe electrocatalyst for efficient oxygen evolution reaction at large current densities

Three-dimensional (3D) self-supporting porous network NiCeO x @NiFeO x electrocatalyst on Ni foam (denotes as NiCe@NiFe/NF-N) is prepared by a simple two step electrodepositing process. NiCe@NiFe/NF-N attains 100 mA/cm 2 at overpotential of 254 mV with Tafel slope of 59.9 mV/dec, which is much lower than that of NiCe@NiFe/NF-P, NiFe@NF, NiCe@NF and also commercial RuO 2 electrocatalysts. Furthermore, the obtained NiCe@NiFe/NF-N electrocatalyst only needs overpotential of 359 mV to deliver high current densities of 1 A/cm 2 and demonstrates excellent stability at such large current densities for 20 h, which is also superior to that of NiCe@NiFe/NF-P electrocatalyst. Further study reveals that the enhanced water oxidation performance of NiCe@NiFe/NF-N electrocatalyst with good stability at high current densities could be attributed to the optimal surface and electronic structures, fast reaction kinetics and high intrinsic catalytic activity. Collectively, such electrocatalyst paves new opportunities for development of low-cost water oxidation electrocatalysts with high current densities for practical water splitting applications.