Rational design of an air-breathing gas-diffusion electrode with oxygen vacancy-rich ZnO for robust and durable H<sub>2</sub>O<sub>2</sub> electrosynthesis
Developing cost-effective and durable cathodes with outstanding oxygen mass transport and selective two-electron oxygen reduction reaction (ORR) is crucial for large-scale H2O2 electrosynthesis. Herein, an oxygen vacancy-rich ZnO-modified air-breathing gas-diffusion electrode (ZnO-V/GDE) was fabrica...
| Autores: | , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/216632 |
| Acceso en línea: | https://hdl.handle.net/2445/216632 |
| Access Level: | acceso embargado |
| Palabra clave: | Oxigen Aigua oxigenada Electroquímica Oxygen Hydrogen peroxide Electrochemistry |
| Sumario: | Developing cost-effective and durable cathodes with outstanding oxygen mass transport and selective two-electron oxygen reduction reaction (ORR) is crucial for large-scale H2O2 electrosynthesis. Herein, an oxygen vacancy-rich ZnO-modified air-breathing gas-diffusion electrode (ZnO-V/GDE) was fabricated, thus eliminating the cost of aeration while achieving remarkable O2 utilization efficiency and H2O2 selectivity. This novel cathode led to ultrahigh H2O2 yield of 1005.2 mg L−1 with selectivity of 74.6 %, outperforming both the raw and ZnO-modified air-breathing GDEs. Moreover, the practical applicability of ZnO-V/GDE was demonstrated by its high stability and effectiveness when treating micropollutants in wastewater by ZnO-V/GDE-based electro-Fenton process. Mechanistic insights unveiled the key roles of oxygen vacancies, which not only facilitate the O2 transport by creating a superhydrophobic interface and provide binding centers to O2, but also reduce the energy barrier of the rate-determining step (OOH*-to-H2O2), eventually enhancing the ORR performance. |
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