TY - JOUR
T1 - Energy transfer-enhanced photocatalytic reduction of protons within quantum dot light-harvesting–Catalyst assemblies
AU - Kodaimati, Mohamad S.
AU - Lian, Shichen
AU - Schatz, George C.
AU - Weiss, Emily A.
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank Prof. Michael Wasielewski for the use of his GC instrument. This work was supported as part of the Center for Bio-Inspired Energy Science, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences, under Award DESC0000989, and by the Materials Research Science and Engineering Center (MRSEC) funded by the National Science Foundation (NSF) under Award DMR-1720139. Theoretical work was supported by NSF Award CHE-1465045. This work made use of the Keck‐II and Electron Probe Instrumentation Center facilities of the Northwestern University Atomic and Nanoscale Characterization Experimental Center, which has received support from the Soft and Hybrid Nanotechnology Experimental Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR‐1121262); the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN.
Funding Information:
We thank Prof. Michael Wasielewski for the use of his GC instrument. This work was supported as part of the Center for Bio-Inspired Energy Science, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences, under Award DE-SC0000989, and by the Materials Research Science and Engineering Center (MRSEC) funded by the National Science Foundation (NSF) under Award DMR-1720139. Theoretical work was supported by NSF Award CHE-1465045. This work made use of the Keck‐II and Electron Probe Instrumentation Center facilities of the Northwestern University Atomic and Nanoscale Characterization Experimental Center, which has received support from the Soft and Hybrid Nanotechnology Experimental Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR‐1121262); the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN.
PY - 2018/8/14
Y1 - 2018/8/14
N2 - Excitonic energy transfer (EnT) is the mechanism by which natural photosynthetic systems funnel energy from hundreds of antenna pigments to a single reaction center, which allows multielectron redox reactions to proceed with high efficiencies in low-flux natural light. This paper describes the use of electrostatically assembled CdSe quantum dot (QD) aggregates as artificial light harvesting–reaction center units for the photocatalytic reduction of H + to H 2 , where excitons are funneled through EnT from sensitizer QDs (sQDs) to catalyst QDs (cQDs). Upon increasing the sensitizer-to-catalyst ratio in the aggregates from 1:2 to 20:1, the number of excitons delivered to each cQD (via EnT) per excitation of the system increases by a factor of nine. At the optimized sensitizer-to-catalyst ratio of 4:1, the internal quantum efficiency (IQE) of the reaction system is 4.0 ± 0.3%, a factor of 13 greater than the IQE of a sample that is identical except that EnT is suppressed due to the relative core sizes of the sQDs and cQDs. A kinetic model supports the proposed exciton funneling mechanism for enhancement of the catalytic activity.
AB - Excitonic energy transfer (EnT) is the mechanism by which natural photosynthetic systems funnel energy from hundreds of antenna pigments to a single reaction center, which allows multielectron redox reactions to proceed with high efficiencies in low-flux natural light. This paper describes the use of electrostatically assembled CdSe quantum dot (QD) aggregates as artificial light harvesting–reaction center units for the photocatalytic reduction of H + to H 2 , where excitons are funneled through EnT from sensitizer QDs (sQDs) to catalyst QDs (cQDs). Upon increasing the sensitizer-to-catalyst ratio in the aggregates from 1:2 to 20:1, the number of excitons delivered to each cQD (via EnT) per excitation of the system increases by a factor of nine. At the optimized sensitizer-to-catalyst ratio of 4:1, the internal quantum efficiency (IQE) of the reaction system is 4.0 ± 0.3%, a factor of 13 greater than the IQE of a sample that is identical except that EnT is suppressed due to the relative core sizes of the sQDs and cQDs. A kinetic model supports the proposed exciton funneling mechanism for enhancement of the catalytic activity.
KW - Artificial photosynthesis
KW - Energy transfer
KW - Proton reduction
KW - Quantum dot assemblies
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U2 - 10.1073/pnas.1805625115
DO - 10.1073/pnas.1805625115
M3 - Article
C2 - 30068607
AN - SCOPUS:85052754466
VL - 115
SP - 8290
EP - 8295
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 33
ER -