Nanostructured Layered Lithium Iridates as Electrocatalysts for Improved Oxygen Evolution Reaction
[EN] We report for the first time the synthesis pathway of nanostructured lithium iridates in molten salts with tunable particle and crystal sizes. The structural analysis confirms that these materials are phase-pure, with a layered alpha- Li2IrO3 structure and a surface area 2 orders of magnitude h...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/205845 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/205845 |
| Access Level: | acceso abierto |
| Palabra clave: | Lithium iridate Nanomaterials Molten salts Electrocatalysis Oxygen evolution reaction Layered materials |
| Sumario: | [EN] We report for the first time the synthesis pathway of nanostructured lithium iridates in molten salts with tunable particle and crystal sizes. The structural analysis confirms that these materials are phase-pure, with a layered alpha- Li2IrO3 structure and a surface area 2 orders of magnitude higher than that of the materials obtained by traditional solid-state methodology. Improved OER activities were obtained compared to the bulk counterpart, given the improved surface area. Intriguingly, the electrocatalytic behavior of this nanoscaled alpha-Li2IrO3 significantly differs from the bulk counterpart. Such a different behavior may arise from the small size of the synthesized materials; thus, surface reactions play a key role. Additionally, the nanoscaled alpha-Li2IrO3 shows good chemical and structural stability; thus, negligible deactivation was observed in KOH and H2SO4 electrolytes with low electrode catalyst loading during 24 h of chronopotentiometry. Besides this stability, these materials show enhanced iridium intrinsic activity with 336 and 181 A gIr-1 in H2SO4 and KOH electrolytes, respectively. This work shows how the design of high-temperature colloidal synthesis yields nanoscaled materials with enhanced and different electrocatalytic properties compared to bulk counterparts and pave the way to the design of electrocatalysts with enhanced mass activity. |
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