• DOI:10.1002/cssc.201600995
• Corpus ID: 30202563

Porphyrin-Sensitized Evolution of Hydrogen using Dawson and Keplerate Polyoxometalate Photocatalysts.

@article{Panagiotopoulos2016PorphyrinSensitizedEO,
  title={Porphyrin-Sensitized Evolution of Hydrogen using Dawson and Keplerate Polyoxometalate Photocatalysts.},
  author={Athanassios A. Panagiotopoulos and Antonios M Douvas and Panagiotis Argitis and Athanassios G. Coutsolelos},
  journal={ChemSusChem},
  year={2016},
  volume={9 22},
  pages={
          3213-3219
        }
}

• Athanassios A. Panagiotopoulos, A. Douvas, +1 author A. Coutsolelos
• Published 23 November 2016
• Chemistry, Medicine
• ChemSusChem

Hydrogen evolution using photocatalytic systems based on artificial photosynthesis is a major approach toward solar energy conversion and storage. In the polyoxometalate-based photocatalytic systems proposed in the past, middle/near UV light irradiation and noble-metal catalysts were mainly used. Although recently polyoxometalates were sensitized in visible light, photosensitizers or catalysts based on noble metals, and/or poor activity of polyoxometalates were generally obtained. Here we show the highly efficient [turnover number (TON)=215] hydrogen evolution induced by the zinc(II) mesotetrakis(N-methyl-pyridinium-4-yl)porphyrin (ZnTMPyP4+ ) sensitization of a series of polyoxometalate catalysts (two Dawson type, P2 Mo18 O626- and P2 W18 O626- anions, and one Keplerate {Mo132 } cluster) in a visible-light-driven, noble-metal-free, and fully water-soluble system. We attributed the high efficiency for hydrogen evolution to the multi-electron reduction of polyoxometalates and found that: (a) both Dawson polyoxometalates exhibit higher hydrogen evolution efficiency upon ZnTMPyP4+ sensitization in relation to the direct photoreduction of those compounds; (b) the P2 Mo18 O626- anion is more efficient (TON=65 vs. 38, respectively) for hydrogen evolution than the P2 W18 O626- anion; and (c) the high nuclearity Keplerate {Mo132 } cluster exhibits the highest efficiency (TON=215) for hydrogen evolution compared with the polyoxometalates studied.