Green synthesis of nitrogen-doped multiporous carbons for oxygen reduction reaction using water-caltrop shells and eggshell waste

• Published in: RSC advances Vol. 11; no. 26; pp. 15738 - 15747
• Main Authors: Hsu, Chun-Han, Pan, Zheng-Bang, Qu, Hau-Ting, Chen, Chuan-Ren, Lin, Hong-Ping, Sun, I-Wen, Huang, Ching-Ying, Li, Chun-Han
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 28.04.2021; The Royal Society of Chemistry
• Subjects: Catalysis; Chemistry; Corrosion resistance; Electrode materials; Electrolytes; Metal air batteries; Methanol; Nitrogen; Oxygen reduction reactions; Shells
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra02100a

A green synthesis method is proposed for the preparation of nitrogen-doped multiporous carbons (denoted as N-MPCs) from water-caltrop shell (WCS) using eggshell waste as both a nitrogen-dopant and an activating agent. It is shown that the surface area, porosity, yield and nitrogen content of the as-prepared N-MPCs can be easily controlled by adjusting the activation temperature. Moreover, in oxygen reduction reaction (ORR) tests performed in O 2 -saturated 0.1 M KOH (aq) electrolyte containing 1.0 M methanol, the N-MPC catalysts show a high ORR stability and good resistance to methanol corrosion. In addition, as a cathode material in Al-air battery tests, the N-MPCs achieve a power density of 16 mW g −1 in a saturated NaCl (aq) electrolyte. Overall, the results show that the N-MPCs have a promising potential as a green and sustainable material for ORR catalysis applications. A green synthetic method is proposed for the preparation of nitrogen-doped multiporous carbons (denoted as N-MPCs) from water-caltrop-shell (WCS) biochar by using eggshell waste as both a nitrogen-dopant and an activating agent.