Porous nitrogen-doped graphdiyne templated from zinc acetylacetonate for enhanced oxygen reduction reaction

Catalysts for the oxygen reduction reaction (ORR) are crucial for energy conversion and storage. Notably, the number of available active sites directly influences the catalyst activity. A large specific surface area is conducive to the creation of more active sites on a catalyst, thereby improving its performance. Zn precursors easily decompose or volatilize at high temperatures, forming a structure with abundant pores, thereby facilitating nitrogen doping. A method for enhancing the ORR activity of nitrogen-doped graphdiyne (GDY) was developed by employing zinc acetylacetonate as a pore-forming agent to increase the exposure of the active N sites. The as-prepared catalyst (denoted as ZnT-N-GDY, where T refers to the template) outperformed Pt/C in the ORR and maintained stable cycling over 2000 cycles in zinc-air batteries, facilitated by the increased exposure of the active N sites, especially pyridinic nitrogen. Based on the specific pore structure of GDY, a highly active metal-free ORR catalyst was synthesized. By introducing zinc precursors as a pore-forming agent, the variety of pores in the GDY structure is further increased, which not only enhances the nitrogen doping content but also facilitates mass transfer during the reaction process. The ZnT-N-GDY exhibits a high-efficient ORR performance and delivers an outstanding stability in zinc-air battery.