Premium
High Turnover in a Photocatalytic System for Water Reduction to Produce Hydrogen Using a Ru, Rh, Ru Photoinitiated Electron Collector
Author(s) -
Arachchige Shamindri M.,
Shaw Ryan,
White Travis A.,
Shenoy Vimal,
Tsui HeiMan,
Brewer Karen J.
Publication year - 2011
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201000399
Subject(s) - photocatalysis , hydrogen , turnover number , photochemistry , chemistry , catalysis , reduction (mathematics) , electron donor , water splitting , electron , inorganic chemistry , chemical engineering , organic chemistry , physics , nuclear physics , geometry , mathematics , engineering
Covalent coupling of Ru II light absorbers to a Rh III electron collecting site through polyazine bridging ligands affords photocatalytic production of H 2 in the presence of visible light and a sacrificial electron donor. A robust photocatalytic system displaying a high turnover of the photocatalyst has been developed using the photoinitiated electron collector [{(bpy) 2 Ru(dpp)} 2 RhBr 2 ] 5+ (bpy=2,2’‐bipyridine; dpp=2,3‐bis(2‐pyridyl)pyrazine) and N , N ‐dimethylaniline in DMF/H 2 O. Studies have shown that increased [DMA], the headspace volume, and the use of DMF solvent improves the systems performance and stability providing mechanistic insight into the deactivation routes of the photocatalytic system. Photolysis of the system at 460 nm generates 20 mL of H 2 in 19.5 h with a maximum Φ =0.023 based on H 2 produced and an overall Φ =0.014 and 280 turnovers of the photocatalyst. The photocatalytic system also displays long‐term photostability with 30 mL of H 2 generated and 420 turnovers in 50 h under the same conditions. Prolonged photolysis provides 820 mol H 2 per mole of catalyst.