Abstract
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 H2, 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.
| Original language | English |
|---|---|
| Pages (from-to) | 8290-8295 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 115 |
| Issue number | 33 |
| DOIs | |
| Publication status | Published - Aug 14 2018 |
Fingerprint
Keywords
- Artificial photosynthesis
- Energy transfer
- Proton reduction
- Quantum dot assemblies
ASJC Scopus subject areas
- General
Cite this
Energy transfer-enhanced photocatalytic reduction of protons within quantum dot light-harvesting–Catalyst assemblies. / Kodaimati, Mohamad S.; Lian, Shichen; Schatz, George C; Weiss, Emily A.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 115, No. 33, 14.08.2018, p. 8290-8295.Research output: Contribution to journal › Article
}
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
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 H2, 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 H2, 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
UR - http://www.scopus.com/inward/record.url?scp=85052754466&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85052754466&partnerID=8YFLogxK
U2 - 10.1073/pnas.1805625115
DO - 10.1073/pnas.1805625115
M3 - Article
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 -