Advances in Hybrid Electrocatalysts for Oxygen Evolution Reactions: Rational Integration of NiFe Layered Double Hydroxides and Nanocarbon

The oxygen evolution reaction (OER) has attracted tremendous explorations in both fundamental and application fields recently, due to its core status in next-generation energy conversion and storage technologies, such as water splitting and metal-air batteries. Transition metal-based compounds, especially the NiFe layered double hydroxides (NiFe LDHs) have been well-established as the most effective and cost-efficient electrocatalysts to boost the sluggish water oxidation and improve the energy efficiency. Nevertheless, a favorable substrate is highly required to expose the poorly conductive active phases and enhance reactivities of OER. In this review, the recent advances concerning synthetic strategies, hierarchical structures, and OER performances of NiFe LDH/nanocarbon hybrid electrocatalysts are summarized. A brief description of OER catalysis, LDHs, and nanocarbon materials is presented firstly, followed by a thorough overview of various investigations according to their synthetic methods and structural characters. The development of high-performance OER catalysts is covered by both a short summary and a presentation of future prospects. This review provides stimulatory knowledge and sheds fresh light into the development of advanced functional materials with a wise hybridization of active phases and conductive substrates.