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Title: Recovery of Active and Efficient Photocatalytic H 2 Production for CdSe Quantum Dots

Recently, colloidal semiconductor quantum dots (QDs) have shown great promise as photocatalysts for the production of chemical fuels by sunlight. Here, the efficiency of photocatalytic hydrogen (H 2) production for integrated systems of large diameter (4.4 nm) CdSe QDs as light harvesting nanoparticles with varying concentrations of nickel-dihydrolipoic acid (Ni-DHLA) small molecule catalysts was measured. While exhibiting excellent robustness and longevity, the efficiency of H 2 production for equimolar catalyst and QDs was relatively poor. However, the efficiency was found to increase substantially with increasing Ni-DHLA:QD molar ratios Surprisingly, this high activity was only observed with the use of 3-mercaptopropionic acid (MPA) ligands, while CdSe QDs capped with dihydrolipoic acid (DHLA) exhibited poor performance in comparison, indicating that the QD capping ligand has a substantial impact on the catalytic performance. Finally, ultrafast transient absorption spectroscopic measurements of the electron transfer (ET) dynamics show fast ET to the catalyst. Importantly, an increase in ET efficiency is observed as the catalyst concentration is increased. Together, these results suggest that for these large QDs, tailoring the QD surface environment for facile ET and increasing catalyst concentrations increases the probability of ET from QDs to Ni-DHLA, overcoming the relatively small driving force for ETmore » and decreased surface electron density for large diameter QDs.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2]
  1. Univ. of Rochester, NY (United States). Dept. of Chemistry
  2. Univ. of Rochester, NY (United States). Dept. of Chemistry and Inst. of Optics
Publication Date:
Grant/Contract Number:
SC0002106; FG02-09ER16121
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Name: Journal of Physical Chemistry. C; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Univ. of Rochester, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY
OSTI Identifier:
1436089

Burke, Rebeckah, Cogan, Nicole M. Briglio, Oi, Aidan, and Krauss, Todd D.. Recovery of Active and Efficient Photocatalytic H2 Production for CdSe Quantum Dots. United States: N. p., Web. doi:10.1021/acs.jpcc.8b01237.
Burke, Rebeckah, Cogan, Nicole M. Briglio, Oi, Aidan, & Krauss, Todd D.. Recovery of Active and Efficient Photocatalytic H2 Production for CdSe Quantum Dots. United States. doi:10.1021/acs.jpcc.8b01237.
Burke, Rebeckah, Cogan, Nicole M. Briglio, Oi, Aidan, and Krauss, Todd D.. 2018. "Recovery of Active and Efficient Photocatalytic H2 Production for CdSe Quantum Dots". United States. doi:10.1021/acs.jpcc.8b01237.
@article{osti_1436089,
title = {Recovery of Active and Efficient Photocatalytic H2 Production for CdSe Quantum Dots},
author = {Burke, Rebeckah and Cogan, Nicole M. Briglio and Oi, Aidan and Krauss, Todd D.},
abstractNote = {Recently, colloidal semiconductor quantum dots (QDs) have shown great promise as photocatalysts for the production of chemical fuels by sunlight. Here, the efficiency of photocatalytic hydrogen (H2) production for integrated systems of large diameter (4.4 nm) CdSe QDs as light harvesting nanoparticles with varying concentrations of nickel-dihydrolipoic acid (Ni-DHLA) small molecule catalysts was measured. While exhibiting excellent robustness and longevity, the efficiency of H2 production for equimolar catalyst and QDs was relatively poor. However, the efficiency was found to increase substantially with increasing Ni-DHLA:QD molar ratios Surprisingly, this high activity was only observed with the use of 3-mercaptopropionic acid (MPA) ligands, while CdSe QDs capped with dihydrolipoic acid (DHLA) exhibited poor performance in comparison, indicating that the QD capping ligand has a substantial impact on the catalytic performance. Finally, ultrafast transient absorption spectroscopic measurements of the electron transfer (ET) dynamics show fast ET to the catalyst. Importantly, an increase in ET efficiency is observed as the catalyst concentration is increased. Together, these results suggest that for these large QDs, tailoring the QD surface environment for facile ET and increasing catalyst concentrations increases the probability of ET from QDs to Ni-DHLA, overcoming the relatively small driving force for ET and decreased surface electron density for large diameter QDs.},
doi = {10.1021/acs.jpcc.8b01237},
journal = {Journal of Physical Chemistry. C},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {5}
}