N,S-codoped carbon microporous structures derived from dead ginkgo leaves as efficient oxygen reduction reaction catalysts for Al–air batteries

Abstract

The exploration and development of efficient and cost-effective oxygen reduction reaction (ORR) catalysts for non-metallic biomass have emerged as a crucial avenue for synthesizing diverse carbon nanomaterials. We synthesized a nitrogen and sulfur co-doped porous three-dimensional graphene-like carbon nanosheet. The present study employed Ginkgo biloba leaves as the raw material, and a significant number of nanopores were obtained through pre-carbonization treatment followed by high-temperature activation treatment using KOH, along with acidification to eliminate inorganic minerals. The specific surface area of the carbon material was increased to 2219.64 m² g⁻¹, resulting in enhanced electrocatalytic performance. The results demonstrate that the optimized N,S co-doped carbon material (TKGLC-2) outperformed 20 wt% Pt/C in all key electrochemical performance parameters as an ORR catalyst. The exceptional ORR properties, ease of preparation, and large surface area suggest that the findings offer a promising prototype template for designing and constructing reliable biochar derived from biomass for potential electrochemical energy and storage applications. This highlights its feasibility as an ORR electrocatalyst in potential applications such as fuel cells and metal–air batteries.