[Zurück]

S. Nandan, N. Gumerova, A. Rajagopal, A. Cherevan, C. Streb, A. Rompel, D. Eder:
"Immobilization of molecular inorganic clusters on TiO2 nanoparticles for photocatalytic water splitting reaction";
Poster: EuroMat 2019, Stockholm, Sweden; 01.09.2019 - 05.09.2019.

Recently, POMs and PTMs triggered a lot of attention as first fully-inorganic homogeneous water-oxidation and water-reduction (photo)catalysts respectively [2, 3]. However, similar to other molecular photocatalysts, they suffer from rapid self-aggregation that leads to the shielding of active sites. Besides, almost all reported POM/PTM photocatalytic systems require the presence of a molecular photosensitizer such as [Ru(bpy)3]2+, to accomplish the light absorption step.
Methods: To address these challenges, we aim to wire the catalytically relevant POM/PTM clusters to high-surface-area semiconducting substrates capable of complementing the light absorption step of a photocatalytic process. Besides, we expect this POM/PTM heterogenization approach to provide a better accessibility of the active sites, while at the same time preventing the catalytic species from deactivation.
Results: In this contribution, I will discuss the covalent and electrostatic immobilization strategies that we developed to attach various POM/PTM clusters - particularly Co-based POMs for oxygen evolution reaction and Mo-based PTMs for hydrogen evolution reaction - on mesoporous metal oxide substrates (particularly TiO­2 nanoparticles). I will present a range of characterization techniques that we applied to study the resulting composites including SEM-EDX to unravel morphology and composition, XPS to elucidate the attachment geometry and ICP-OES to investigate the immobilization stability.
Conclusions: Thus, immobilization of POM/PTMs on TiO2 nanoparticles have been accomplished and experimental data shown on how efficiently these clusters can be utilized as co-catalysts in heterogeneous photocatalytic water splitting reactions.