title: Photodriven charge separation dynamics in CdSe/ZnS core/shell quantum dot/cobaloxime hybrid for efficient hydrogen production.
abstract: Photodriven charge-transfer dynamics and catalytic properties have been investigated for a hybrid system containing CdSe/ZnS core/shell quantum dots (QDs) and surface-bound molecular cobaloxime catalysts. The electron transfer from light-excited QDs to cobaloxime, revealed by optical transient absorption spectroscopy, takes place with an average time constant of 105 ps, followed a much slower charge recombination process with a time constant of ≫3 ns. More interestingly, we also observed photocatalytic hydrogen generation by this QD/cobaloxime hybrid system, with >10,000 turnovers of H(2) per QD in 10 h, using triethanolamine as a sacrificial electron donor. These results suggest that QD/cobaloxime hybrids succeed in coupling single-photon events with multielectron redox catalytic reactions, and such systems could have potential applications in long-lived artificial photosynthetic devices for fuel generation from sunlight.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Jier
authors.initials: J
authors.lastname: Huang
authors.forename: Karen L
authors.initials: KL
authors.lastname: Mulfort
authors.forename: Pingwu
authors.initials: P
authors.lastname: Du
authors.forename: Lin X
authors.initials: LX
authors.lastname: Chen