Towards metal-free nitrogen-doped graphene aerogels as efficient electrocatalysts in hydrogen evolution reaction
Graphene-based materials have been researched to substitute traditional Pt-based electrocatalysts in the hydrogen evolution reaction (HER) due to its strong electrical conductivity, easy functionalization, and cheaper synthesis. Doping graphene with heteroatom is a simple way of obtaining original a...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad de Castilla-La Mancha |
| Repositorio: | RUIdeRA. Repositorio Institucional de la UCLM |
| OAI Identifier: | oai:ruidera.uclm.es:10578/33504 |
| Acceso en línea: | https://doi.org/10.1016/j.flatc.2023.100554 https://hdl.handle.net/10578/33504 |
| Access Level: | acceso abierto |
| Palabra clave: | Aerogel Calcination temperature Dotación de nitrógeno HER Nitrogen-doping Óxido de grafeno reducido Reduced graphene oxide Temperatura de calcinación |
| Sumario: | Graphene-based materials have been researched to substitute traditional Pt-based electrocatalysts in the hydrogen evolution reaction (HER) due to its strong electrical conductivity, easy functionalization, and cheaper synthesis. Doping graphene with heteroatom is a simple way of obtaining original and active electrocatalysts. Moreover, the nitrogen on it had a positive effect on HER performance. By using a reducing agent with nitrogen while synthesising graphene-based aerogels nitrogen-doped catalysts were obtained. In addition, a better reduction rate, higher crystallography parameters and a more porous material structure were reached. The aerogels were synthesised in an one-pot hydrothermal process, in which the graphene sheets were assembled. This was followed by freeze-drying, which fixed the carbon matrix structure. As a result, the final aerogel had a 3D structure that eased mass transfer and enhanced catalytic activity, reaching an overpotential of -10 mAcm-2 at 101 mV vs RHE (?10 = 101 mV). The amount of quaternary type nitrogen generated during synthesis had a strong influence on electrocatalytic behaviour in HER. Then, quaternary nitrogen and surface area (up to 397 m2/g) were maximized to ensure a higher current density. Moreover, an effective aerogel was prepared with half the solvent per batch, as this was essential for expanding the synthesis to an industrial scale. A final calcination step resulted crucial to improve the metal-free aerogel HER performance. |
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