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Photo‐recycling the Sacrificial Electron Donor: Towards Sustainable Hydrogen Evolution in a Biphasic System
Author(s) -
Ge Peiyu,
Hojeij Mohamad,
Scanlon Micheál D.,
Girault Hubert H.
Publication year - 2020
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.202000844
Subject(s) - nanoparticle , aqueous solution , aqueous two phase system , electron donor , photocatalysis , phase (matter) , chemical engineering , materials science , photochemistry , chemistry , semiconductor , nanotechnology , optoelectronics , organic chemistry , catalysis , engineering
H 2 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 H 2 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. TiO 2 (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.