A microwave-assisted decoration of carbon nanotubes with Fe3O4 nanoparticles for efficient electrocatalytic oxygen reduction reaction

The electrocatalytic oxygen reduction process (ORR) is one of the possible methods for producing sus-tainable energy, but its slow kinetics necessitates the use of inexpensive and efficient catalysts. Herein, Fe3O4 nanoparticles (Fe3O4 NPs) were loaded onto multiwall carbon nanotubes (Fe3O4@CNTs) using a single-step microwave-assisted strategy. The prepared Fe3O4@CNTs composite was characterized via mul-tiple analytical techniques, and the results suggested a thin film of Fe3O4 NPs coating on the CNT surface, having a high specific surface area and pore volume. The prepared Fe3O4@CNTs composite exhibited a positive shift in ORR half-wave potential of 240 and 20 mV with respect to Fe3O4 and 20% Pt/C catalysts, respectively. The improved ORR activity of the Fe3O4@CNTs composite can be attributed to the synergetic interaction between CNTs and Fe3O4, which is also supported by theoretical simulations. Furthermore, the Fe3O4@CNTs composite showed superior cycling stability and remarkable methanol tolerance, proving its applicability as an ORR catalyst at a practical level. This research will aid in the development of microwave -based strategies for producing efficient ORR catalysts. It will also give a basic understanding of the re-lationships between composition, structure, and activity.(c) 2023 Elsevier B.V. All rights reserved.