The Ni(OH)2 interlayer modified spherical NiFe layered double hydroxides for enhanced alkaline oxygen evolution reaction performance

Heterogeneous interface engineering is an ideal technique for the rational design of efficient and low-cost electrocatalysts for oxygen evolution reactions (OER). In this study, a complex hydrothermal-electrodeposition composite approach was used to insert a Ni(OH)2 interlayer into the tiny gaps between the layers of NiFe layered double hydroxides (NiFe LDHs), and the interlayer's influence on OER performance was examined. Benefiting from the support of Ni(OH)2 interlayer, the resulting Ni(OH)2/NiFe LDHs could withstand 5000 CV-AST tests with just a 6 mV overpotential increase, as well as 50 h of long-term operation with negligible activity loss on a potential of 1.724 VRHE. Meanwhile, in the OER process, the Ni(OH)2/NiFe LDHs exhibit 220 mV overpotential and 48.5 mV dec−1 Tafel slope in 1 M KOH solution, which is superior to NiFe LDHs, RuO2, and IrO2. Additionally, Ni(OH)2/NiFe LDHs show a high-polarization-potential stability during i-t tests. At 1.824 VRHE, the Ni(OH)2/NiFe LDHs could afford 12 h operation with ∼0.35 % activity loss, which was better than on a low potential of 1.624 VRHE (12 h, ∼8.4 % activity loss). This composite strategy may provide an effective method for optimizing other LDHs, as well as a new route for building high-activity and durable OER catalysts for practical water splitting.