The Power of Catalytic Centers and Ascorbate in Boosting the Photocatalytic Hydrogen Evolution Performance of TpDTz 2D-COF
The photocatalytic hydrogen evolution activity of a model 2D covalent organic framework (TpDTz) containing a thiazolo[5,4-d]thiazole (DTz) electron acceptor and triformylphloroglucinol (Tp) electron donor groups is enhanced by combining it with well-defined catalytic centers and suitable sacrificial...
| Autores: | , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/420432 |
| Acceso en línea: | http://hdl.handle.net/10261/420432 https://api.elsevier.com/content/abstract/scopus_id/105027588686 |
| Access Level: | acceso abierto |
| Palabra clave: | Catalysts Charge transfer Covalent organic frameworks Evolution reactions Metal nanoparticles |
| Sumario: | The photocatalytic hydrogen evolution activity of a model 2D covalent organic framework (TpDTz) containing a thiazolo[5,4-d]thiazole (DTz) electron acceptor and triformylphloroglucinol (Tp) electron donor groups is enhanced by combining it with well-defined catalytic centers and suitable sacrificial electron donors. Platinum nanoparticles (PtNPs) with an average diameter of 2.7 ± 0.4 nm achieve rates up to 106 000 μmol H2 g-1 h-1 (5% Pt w/w). The best system requires the use of ascorbic acid/ascorbate buffer, which has been demonstrated to enhance the photoluminescence of TpDTz by forming aggregates while efficiently extracting charges from the excited TpDTz (TpDTz*). The productive charge extraction by the PtNPs from TpDTz* is also supported by steady state and time-resolved photoluminescence studies. All these factors combined with the high catalytic activity of PtNPs catalytic centers lead to the high performance of the overall system. In addition, a noble metal-free molecular catalyst based on a tetraazamacrocyclic cobalt complex has been identified as a good alternative catalyst candidate, efficiently quenching TpDTz photoluminescence. Under optimal conditions, the cobalt-based system achieves catalytic rates of 10 400 μmol H2 g-1 h-1 (1% Co w/w), which is only three times slower than the noble metal-based PtNPs system (1% Pt w/w, 28 300 μmol H2 g-1 h-1). By using controlled catalytic centers, it was possible to identify the factors limiting the hydrogen evolution photocatalytic activity of TpDTz allowing one to minimize undesired pathways and enhancing its performance by 2 orders of magnitude. |
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