A networked iron and nitrogen-doped ZIF-8/MWCNTs heterostructure for oxygen reduction reaction

Qingxia Li; Dongmei Song; Xinxing Zhan; Xin Tong; Changgang Hu; Juan Tian

doi:10.1063/5.0201482

A networked iron and nitrogen-doped ZIF-8/MWCNTs heterostructure for oxygen reduction reaction

J Chem Phys. 2024 May 28;160(20):204704. doi: 10.1063/5.0201482.

Authors

Qingxia Li¹, Dongmei Song¹, Xinxing Zhan^{1

2}, Xin Tong^{1

2}, Changgang Hu^{1

2}, Juan Tian^{1

2}

Affiliations

¹ School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550025, China.
² Key Laboratory for Functional Materials Chemistry of Guizhou Province, Guiyang 550025, China.

PMID: 38775246
DOI: 10.1063/5.0201482

Abstract

Zeolitic Imidazolate Frameworks-8 (ZIF-8) is commonly used as an ideal precursor for non-noble metal catalysts because of its high specific surface area, ultra-high porosity, and N-rich content. Upon pyrolyzing ZIF-8 at 900 °C in Ar, the resulting material, referred to as Z8, displayed good activity toward the oxygen reduction reaction (ORR). Then the ZIF-8 was mixed with various conductive carbon materials, such as multiwall carbon nanotubes (MWCNTs), Acetylene black (ACET), Vulcan XC-72R (XC-72R), and Ketjenblack EC-600JD (EC-600JD), to form Z8 composites. The Z8/MWCNTs composite exhibited enhanced ORR activity owing to its network structure, meso-/microporous hierarchical porous structure, improved electrical conductivity, and graphitization. Subsequently, iron and nitrogen co-doping is achieved through the pyrolysis of a mixture comprising Fe, N precursor, and ZIF-8/MWCNTs, which is denoted as FeN-Z8/MWCNTs. The intrinsically high electrical conductivity of MWCNTs facilitated efficient electron transfer during the ORR, while the meso-/microporous hierarchical porous structure and network structure of Fe, N co-doped ZIF-8/MWCNTs promoted oxygen transport. The presence of Fe-containing species in the catalyst acted as activity centers for ORR. This strategy of preparing Z8 composites and modifying them with Fe, N co-doping offers an insightful approach to designing cost-effective electrocatalysts.