Improved Photocatalytic H2 Evolution by Cobaloxime-Tethered Imidazole-Functionalized Periodic Mesoporous Organosilica
![Thumbnail](/bitstream/handle/10396/24611/hydrogen-04-00008.pdf.jpg?sequence=3&isAllowed=y)
View/ Open
Author
Navarro, M. Ángeles
Martín, Miguel
Ruiz, José Rafael
Jiménez-Sanchidrián, César
Romero-Salguero, F.J.
Esquivel, Dolores
Publisher
MDPIDate
2023Subject
CobaloximePeriodic mesoporous organosilicas
Photocatalysis
Hydrogen evolution reaction
Primary axial coordination
METS:
Mostrar el registro METSPREMIS:
Mostrar el registro PREMISMetadata
Show full item recordAbstract
Molecular cobaloxime-based heterogeneous systems have attracted great interest during the last decades in light-driven hydrogen production. Here, we present a novel cobaloxime-tethered periodic mesoporous organosilica (PMO) hybrid (Im-EtPMO-Co) prepared through the immobilization of a molecular cobaloxime complex on the imidazole groups present in ethylene-bridged PMO. The successful assembly of a molecular cobaloxime catalyst via cobalt-imidazole axial ligation has been evidenced by several techniques, such as 13C NMR, Raman spectroscopy, ICP-MS, and XPS. The catalytic performance of Im-EtPMO-Co catalyst was essayed on the hydrogen evolution reaction (HER) under visible light in presence of a photosensitizer (Eosin Y) and an electron donor (TEOA). It showed an excellent hydrogen production of 95 mmol hydrogen at 2.5 h, which corresponded to a TON of 138. These results reflect an improved photocatalytic activity with respect to its homogenous counterpart [Co(dmgH)2(Im)Cl] as well as a previous cobaloxime-PMO system with pyridine axial ligation to the cobaloxime complex.