Polymethylhydrosiloxane-modified gas-diffusion cathode for more efficient and durable H2O2 electrosynthesis in the context of water treatment
On-site H2O2 electrosynthesis via two-electron oxygen reduction reaction (ORR) is attracting great interest forwater treatment. The use of carbon black-based gas-diffusion electrodes (GDEs) is especially appealing, but theiractivity, selectivity and long-term stability must be improved. Here, a faci...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/206789 |
| Acceso en línea: | https://hdl.handle.net/2445/206789 |
| Access Level: | acceso abierto |
| Palabra clave: | Depuració de l'aigua Reacció d'oxidació-reducció Electroquímica Water purification Oxidation-reduction reaction Electrochemistry |
| Sumario: | On-site H2O2 electrosynthesis via two-electron oxygen reduction reaction (ORR) is attracting great interest forwater treatment. The use of carbon black-based gas-diffusion electrodes (GDEs) is especially appealing, but theiractivity, selectivity and long-term stability must be improved. Here, a facile GDEs modification strategy usingtrace polymethylhydrosiloxane (PMHS) allowed reaching a outstanding H2O2 production, outperforming theconventional polytetrafluoroethylene (PTFE)-GDE (1874.8 vs 1087.4 mg L-1 at 360 min). The superhydrophobicityconferred by PMHS endowed the catalytic layer with high faradaic efficiencies (76.2%-89.7%)during long-term operation for 60 h. The electrochemical tests confirmed the high activity and selectivity of thePMHS-modified GDE. Moreover, the efficient degradation of several micropollutants by the electro-Fentonprocess demonstrated the great potential of the new GDE. An in-depth understanding of the roles of PMHSfunctional groups is provided from DFT calculations: the -CH3 groups contribute to form a superhydrophobicinterface, whereas Si-H and as-formed Si-O-C sites modulate the coordination environment of active carboncenters. |
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