Self-doping active sites in microbe-derived carbonaceous electrocatalysts for the oxygen reduction reaction performance

Microorganisms are rich in heteroatoms, which can be self-doped to form active sites during pyrolysis and loaded on microbe-derived carbonaceous materials. In recent years, microbe-derived carbonaceous materials, characterized with abundant self-doping sites, have been continuously developed as cost-effective electrocatalysts for oxygen reduction reaction (ORR). To fully unlock the catalytic potential of microbe-derived carbonaceous materials, a comprehensive analysis of catalytic sites and mechanisms for ORR is essential. This paper provides a summary of the ORR catalytic performance of microbe-derived carbonaceous materials reported to date, with a specific focus on the self-doping sites introduced during their pyrolytic fabrication. It highlights the mono- or co-doping sites involving nonmetallic elements such as oxygen (O), nitrogen (N), phosphorus (P), and sulfur (S) atoms, as well as covers the doping of metallic iron (Fe) atoms with various coordination configurations in microbe-derived carbonaceous materials. Understanding the impact of these self-doping sites on ORR catalytic performance can guide the design of doping sites in microbe-derived carbonaceous materials. This approach has the potential to maximize electrocatalytic activity of microbe-derived carbonaceous materials and contributes to the development of more efficient and cost-effective carbonaceous electrocatalysts.