Scalable microwave-assisted synthesis of iron oxide aerogels: Tuning morphology, crystallinity, and electrocatalytic performance
Microwave-assisted iron oxide aerogels were prepared using different microwave heating systems to study the effect of synthesis pressure on their final properties. Additionally, other parameters, such as the ratio of reagents, time and temperature of synthesis, were also evaluated. It was found that...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2026 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/413210 |
| Acesso em linha: | http://hdl.handle.net/10261/413210 https://api.elsevier.com/content/abstract/scopus_id/105023954022 |
| Access Level: | acceso abierto |
| Palavra-chave: | Transition metal aerogels Electrocatalyst Microwave heating Operation variables Oxygen reduction reaction Sol-gel synthesis http://metadata.un.org/sdg/9 http://metadata.un.org/sdg/7 Ensure access to affordable, reliable, sustainable and modern energy for all Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation |
| Resumo: | Microwave-assisted iron oxide aerogels were prepared using different microwave heating systems to study the effect of synthesis pressure on their final properties. Additionally, other parameters, such as the ratio of reagents, time and temperature of synthesis, were also evaluated. It was found that iron oxide aerogels synthesized at atmospheric pressure exhibit structural and morphological properties comparable to those produced under pressure, positioning the use of open vessels as a scalable and efficient alternative for the mass production of iron oxide aerogels by microwave heating. Besides, the morphology, structure, and degree of crystallinity can be easily fine-tuned by modifying the ratio between reagents and time and temperature of synthesis. An excess of reducing or metallic precursor favours the formation of cluster structures, while flake-type structures are obtained employing similar proportions. However, the flakes may evolve into clusters by increasing the time of synthesis. Regarding the structural composition, reducing agent-rich conditions favour the synthesis of magnetite, whereas higher metallic precursor concentrations promote goethite formation. However, higher synthesis temperatures shift the phase balance toward magnetite and enhance crystallinity. The electrocatalytic performance of iron oxide aerogels towards the oxygen reduction reaction may be improved by the proper combination of morphology, structure, and degree of crystallinity. Specifically, clusters composed of amorphous goethite result in the most promising material, particularly after applying a reduction process. These findings underscore the versatility of microwave-assisted sol-gel synthesis to modulate the iron oxide aerogel properties and tailor them to the electrocatalyst requirements for the oxygen reduction reaction. |
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