Recent advances in carbon substrate supported nonprecious nanoarrays for electrocatalytic oxygen evolution

The oxygen evolution reaction (OER) plays a crucial role in sustainable energy conversion and storage including water splitting, fuel cells, and metal-air batteries. The design and exploration of earth-abundant OER electrocatalysts with low cost, high-performance, and durability are of paramount importance. Nanoarray catalysts constructed on free-standing carbon substrates have drawn significant attention owing to their high conductivity, fascinating nanostructures, and abundant active sites. This review presents recent progress toward advanced self-supported catalysts for the OER. We have systematically overviewed diverse synthetic approaches for the preparation of self-supported electrocatalysts with selected examples of metal oxides, metal hydroxides/oxyhydroxides, metal phosphides, metal sulfides, metal selenides, and metal-organic frameworks (MOFs) and their derivatives. State-of-the-art strategies to improve OER catalytic activity and stability of self-supported catalysts are provided including interface and defect engineering as well as heteroatom-doping. Finally, an overview of current challenges and future prospects for developing more promising carbon substrate supported nanoarray catalysts is provided.