Nanostructured Carbon Based Heterogeneous Electrocatalysts for Oxygen Evolution Reaction in Alkaline Media

Development of cost-effective and highly efficient oxygen evolution reaction (OER) electrocatalysts has become a vital project of renewable energy technologies. The OER is critical for a variety of electrochemical energy devices such as water electrolyzers, metal-air batteries, CO₂ reduction, and electrosynthesis of ammonia. Compared to extensively studied metal oxide catalysts, graphitized carbon catalysts have been newly emerged as promising OER catalysts especially in less corrosive alkaline media, due to their low cost, high electrical conductivity, unique physicochemical properties, and excellent electrocatalytic performances. In this review, we discussed recent advances in nanostructured carbon electrocatalysts. At first, metal-free OER carbon electrocatalysts including single- and multi-heteroatom doping and edge- and defect-rich defects are introduced. Then, transition metal and heteroatom co-doped nanocarbons are summarized including Co−N−C, Ni−N−C, and Fe-N−C. In addition, carbon based hybrid electrocatalysts are highlighted, which include carbon based transition metal nitrides (TMN_x), sulfides (TMS_x), and selenides (TMSe_x), and phosphides (TMP_x). Finally, current challenges and perspective for future research on carbon-based OER catalysts are outlined.