A facile synthesis of FeS/Fe3C nanoparticles highly dispersed on in situ grown N-doped CNTs as cathode electrocatalysts for microbial fuel cells

Zhuoyue Chen; Yingyu Lin; Yuying Zhou; Yuxian Yang; Yaotang Zhong; Mengqing Xu; Weishan Li

doi:10.1039/d3cp02152a

A facile synthesis of FeS/Fe₃C nanoparticles highly dispersed on in situ grown N-doped CNTs as cathode electrocatalysts for microbial fuel cells

Phys Chem Chem Phys. 2023 Aug 16;25(32):21191-21199. doi: 10.1039/d3cp02152a.

Authors

Zhuoyue Chen¹, Yingyu Lin¹, Yuying Zhou¹, Yuxian Yang¹, Yaotang Zhong¹, Mengqing Xu^{1

2}, Weishan Li^{1

2}

Affiliations

¹ School of Chemistry, South China Normal University, Guangzhou 510006, China. liwsh@scnu.edu.cn.
² National and Local Joint Engineering Research Center of MPTES in High Energy and Safety LIBs, Engineering Research Center of MTEES (Ministry of Education), and Key Lab. of ETESPG (GHEI), South China Normal University, Guangzhou 510006, China.

PMID: 37530031
DOI: 10.1039/d3cp02152a

Abstract

A novel composite of iron sulfide, iron carbide and nitrogen carbides (Nano-FeS/Fe₃C@NCNTs) as a cathode electrocatalyst for microbial fuel cells (MFCs) is synthesized by a one-pot solid state reaction, which yields a unique configuration of FeS/Fe₃C nanoparticles highly dispersed on in situ grown nitrogen-doped carbon nanotubes (NCNTs). The highly dispersed FeS/Fe₃C nanoparticles possess large active sites, while the NCNTs provide an electronically conductive network. Consequently, the resultant Nano-FeS/Fe₃C@NCNTs exhibit excellent electrocatalytic activity towards the oxygen reduction reaction (ORR), with a half-wave potential close to that of Pt/C (about 0.88 V vs. RHE), and enable MFCs to deliver a power density of 1.28 W m^-2 after two weeks' operation, which is higher than that of MFCs with Pt/C as the cathode electrocatalyst (1.02 W m^-2). Theoretical calculations and experimental data demonstrate that there is a synergistic effect between Fe₃C and FeS in Nano-FeS/Fe₃C@NCNTs. Fe₃C presents a strong attraction and electron-donating tendency to oxygen molecules, serving as the main active component, while FeS reduces charge transfer resistance by transferring electrons to Fe₃C, synergistically improving the kinetics of the ORR and power density of MFCs.