Borocarbonitride materials as metal-free catalysts for advanced catalysis

Borocarbonitride (BCN) materials, emerging as metal-free catalysts, have garnered considerable interest owing to their plentiful availability; their impressive tolerance across diverse pH levels; and the tunable capability of their B, N-doped carbon network and band structures. These materials exhibit impressive performance in various catalytic reactions related to energy conversion and organic synthesis. This review summarizes the most recent advancements in the synthesis methods and catalytic applications of BCN catalysts and discusses the synergistic promotion between B and N heteroatoms embedded within the carbon network structures in catalytic processes, thereby offering advanced catalytic processes and perspectives on comprehending the underlying reaction mechanisms. The review begins with an introduction to the structure and theoretical simulation of BCN materials, followed by a summary and analysis of various synthesis methods reported in the most recent years. Subsequently, we offer a detailed discussion regarding real active site structures present on the surface of BCN materials in oxidative dehydrogenation, reduction reactions and energy conversion processes (water splitting, CO₂ reduction, oxygen reduction reaction, and N₂ reduction reaction) as well as photocatalytic reactions (H₂ evolution, CO₂ reduction, and organic synthesis), contributing novel insights into the nature of reactive sites involved and band characteristics. Ultimately, the existing issues and challenges encountered in current BNC catalyst research are highlighted, and accordingly, promising research directions for future efforts are proposed.