Fe/N codoped porous graphitic carbon derived from macadamia shells as an efficient cathode oxygen reduction catalyst in microbial fuel cells

Haoming Ning; Zhi Zhang; Chunhai Shi; Xiaolei Ma; Jian Li; Hongyi Zhu; Jiawei Hu

doi:10.1039/d2ra04214b

Fe/N codoped porous graphitic carbon derived from macadamia shells as an efficient cathode oxygen reduction catalyst in microbial fuel cells

RSC Adv. 2022 Oct 24;12(46):30145-30156. doi: 10.1039/d2ra04214b. eCollection 2022 Oct 17.

Authors

Haoming Ning^{1

2}, Zhi Zhang^{1

2}, Chunhai Shi³, Xiaolei Ma³, Jian Li³, Hongyi Zhu^{1

2}, Jiawei Hu^{1

2}

Affiliations

¹ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University Chongqing 400045 China zhangzhicqu@cqu.edu.cn.
² College of Environment and Ecology, Chongqing University Chongqing 400045 China.
³ Northwest China Municipal Engineering Northwest Design and Research Institute Lanzhou 730000 China 252440589@qq.com.

Abstract

In this study, Fe/N codoped porous graphitic carbon derived from macadamia shells was prepared at different temperatures as cathodic catalysts for microbial fuel cells (MFCs), with K₂FeO₄ as a bifunctional catalyst for porosity and graphitization. The catalyst prepared at 750 °C (referred to as MSAC-750) showed a large specific surface area (1670.3 m² g^-1), graphite structure, and high pyridine-N and Fe-N _X contents. Through the electrochemical workstation test, MSAC-750 shows excellent oxygen reduction reaction (ORR) activity, with an onset potential of 0.172 V and a half-wave potential of -0.028 V (vs. Ag/AgCl) in a neutral medium, and the ORR electron transfer number is 3.89. When applied to the MFCs as cathodic catalysts, a higher maximum power density and voltage of 378.68 mW m^-2 and 0.425 V were achieved with the MSAC-750 catalyst and is superior to that of the Pt/C catalyst (300.85 mW m^-2 and 0.402 V). In this case, a promising method is hereby established for the preparation of an excellent electrochemical catalyst for microbial fuel cells using inexpensive and easily available macadamia shells.