Tri-functional Fe-based electrocatalyst with sturdy three-dimensional frame construction for the ORR, OER and HER

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 12; no. 3; pp. 19344 - 19351
• Main Authors: Liang, Haixia, Li, Jian, Zhang, Jinli, Peng, Wencai, Li, Jun, Liu, Jichang
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 30.07.2024
• Subjects: Cementite; Chemical reduction; Clean energy; Electrocatalysts; Electrochemistry; Electrostatic properties; Energy conversion; Green energy; Hemin; High temperature; Hydrogen evolution reactions; Iron carbides; Metal air batteries; Oxygen evolution reactions; Oxygen reduction reactions; Pyrolysis; Rechargeable batteries; Renewable energy; Silicon dioxide; Water splitting; Zinc-oxygen batteries
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta01958j

Oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalysis have an important role in rechargeable zinc-air batteries (ZABs) and water splitting and have received extensive attention over the years. Therefore, the design and development of efficient and economical multifunctional electrocatalysts is currently considered an important subject in the field of green and renewable energy. In this paper, a simple and reproducible SiO 2 templating strategy is designed to utilize natural hemin as a source of Fe-N-C material. Hemin is adsorbed onto the surface of SiO 2 through electrostatic interaction, which allows hemin to stretch along the surface of SiO 2 spheres during high-temperature pyrolysis. The final product named Fe 3 C-Fe/NC-800 with abundant cavities and a sturdy 3D framework structure shows excellent ORR, OER and HER activities. Theoretical calculations show that the synergistic interaction between Fe 3 C and FeN 4 sites reduces the energy barrier during the electrochemical reaction and improves the ORR, OER, and HER performance. Based on its superior tri-functional activity, Fe 3 C-Fe/NC-800 finds potential applications in ZABs and overall water-splitting devices. This work will provide insights into the design and preparation of electrocatalysts used in clean energy conversion devices. The catalyst Fe 3 C-Fe/NC-800 with a hollow interconnected honeycomb structure was prepared using a hard template strategy. It showed excellent ORR, OER and HER properties and favourable applications in ZABs and the overall water splitting device.