Photo-recycling the Sacrificial Electron Donor: Towards Sustainable Hydrogen Evolution in a Biphasic System |
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| Authors: | Dr Peiyu Ge Dr Mohamad Hojeij Dr Micheál D Scanlon Prof Hubert H Girault |
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| Institution: | 1. Laboratoire d'Électrochimie Physique et Analytique, École Polytechnique Fédérale de Lausanne, EPFL, Valais Wallis, Rue de l'industrie, 17, 1950 SION, Switzerland;2. The Bernal Institute and Department of Chemical Sciences, University of Limerick (UL), Limerick, V94 T9PX Ireland |
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| Abstract: | H2 may be evolved biphasically using a polarised liquid|liquid interface, acting as a “proton pump”, in combination with organic soluble metallocenes as electron donors. Sustainable H2 production requires methodologies to recycle the oxidised donor. Herein, the photo-recycling of decamethylferrocenium cations (DcMFc+) using aqueous core-shell semiconductor CdSe@CdS nanoparticles is presented. Negative polarisation of the liquid|liquid interface is required to extract DcMFc+ to the aqueous phase. This facilitates the efficient capture of electrons by DcMFc+ on the surface of the photo-excited CdSe@CdS nanoparticles, with hydrophobic DcMFc subsequently partitioning back to the organic phase and resetting the system. TiO2 (P25) and CdSe semiconductor nanoparticles failed to recycle DcMFc+ due to their lower conduction band energy levels. During photo-recycling, CdS (on CdSe) may be self-oxidised and photo-corrode, instead of water acting as the hole scavenger. |
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| Keywords: | liquid-liquid interfaces hydrogen evolution reaction metallocenes nanoparticles sacrificial electron donor CdSe@CdS nanoparticles |
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