Synthesis of oxygen-rich carbon materials as metal-free catalysts for oxygen reduction reaction in seawater electrolyte

• Published in: Vacuum 2025-02, Vol.232, p.113834, Article 113834
• Main Authors: Li, Jiangpeng, He, Qiuchen, Zhan, Su, Zhou, Lin, Zhang, Junjie, Qiao, Yuchen, Zhao, Ziming, Yang, Dehui, Jiang, Wenjun, Zhou, Feng
• Format: Article
• Language: English
• Subjects: Biomass-derived carbon; Metal-free catalysts; Oxygen containing functional groups; Oxygen reduction reaction; Seawater electrolyte
• ISSN: 0042-207X
• DOI: 10.1016/j.vacuum.2024.113834

Compared to conventional aqueous metal-air batteries, seawater batteries provide a promising strategy for the sustainable energy conversion and storage systems. However, the intricate ionic environment of seawater, in particular, Cl− significantly restraint the oxygen reduction reaction (ORR) activity of the catalysts. Herein, mesoporous carbon materials with abundant oxygen-containing functional groups were simply fabricated as the cost-effective catalysts from the biowaste Ginkgo biloba, exhibiting prominent stability and ORR activity with a 4e− path selectivity up to 92 % in seawater electrolyte. Structure characterization and ORR experimental results indicated the ORR performance was significantly modulated by the C-O-C in carbon matrix, and the synergistic of C-O-C and N-containing configuration may further enhance the dissociation of O-O of ∗OOH, resulting in an optimized 4e− path selectivity. Additionally, the Ginkgo biloba derived catalysts displayed an overpotential of 580 mV for at 10 mA/cm2 more negative than that of the previously reported commercial Ir/C in seawater electrolyte. This study highlights the synthesis of sustainable and cost-effective catalysts for seawater batteries, offering a strategy for designing metal-free catalysts of seawater battery, and promoting the advancement of sustainable energy conversion and storage technologies. •Oxygen-rich mesoporous carbon was prepared by a simple annealing method from biowaste materials.•Ginkgo biloba derived carbon exhibits an excellent ORR activity with a 4e−-path selectivity of 92 % in seawater electrolyte.•4e− ORR performance was optimized by the synergistic of C-O-C and N-containing configuration.