Interfacial microenvironment modulation enhancing catalytic kinetics of bimetallic (oxy)hydroxide heterostructures for highly efficient oxygen evolution reaction

Water splitting is a promising hydrogen production technology limited by the slow kinetic oxygen evolution reaction (OER). The development of highly active and robust OER catalysts is in high demand. A series of three-dimensional (3D) self-supported FeOOH@Ni(OH) 2 heterostructures supported on nickel foam are synthesized and used as efficient OER catalysts using a simple hydrothermal method . The benefits of the appropriate 3D nanoflower morphology, the large number of FeOOH nanosheets adhered on the nanoflower surface, the formation of heterogeneous interfaces, and the synergistic effect of Ni(OH) 2 and FeOOH significantly improve the OER catalytic performance of the material. The optimal catalyst in 1 M KOH, alkaline artificial seawater (1 M KOH + 1 M NaCl), and alkaline nature seawater (1 M KOH + seawater) require only 285, 286, and 325 mV overpotential, respectively, to achieve 100 mA cm −2 current density and has robust stability. This study contributes to the rational design of interface-engineered heterostructures for seawater splitting by synthesizing high catalytic activity catalysts.