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Daniel, Quentin
Publications (6 of 6) Show all publications
Fan, L., Zhang, P., Zhang, B., Daniel, Q., Timmer, B., Zhang, F. & Sun, L. (2018). 3D Core-Shell NiFeCr Catalyst on a Cu Nanoarray for Water Oxidation: Synergy between Structural and Electronic Modulation. ACS ENERGY LETTERS, 3(12), 2865-2874
Open this publication in new window or tab >>3D Core-Shell NiFeCr Catalyst on a Cu Nanoarray for Water Oxidation: Synergy between Structural and Electronic Modulation
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2018 (English)In: ACS ENERGY LETTERS, ISSN 2380-8195, Vol. 3, no 12, p. 2865-2874Article in journal (Refereed) Published
Abstract [en]

Low cost transition metal-based electrocatalysts for water oxidation and understanding their structure-activity relationship are greatly desired for clean and sustainable chemical fuel production. Herein, a core-shell (CS) NiFeCr metal/metal hydroxide catalyst was fabricated on a 3D Cu nanoarray by a simple electrodeposition-activation method. A synergistic promotion effect between electronic structure modulation and nanostructure regulation was presented on a CS-NiFeCr oxygen evolution reaction (OER) catalyst: the 3D nanoarchitecture facilitates the mass transport process, the in situ formed interface metal/metal hydroxide heterojunction accelerates the electron transfer, and the electronic structure modulation by Cr incorporation improves the reaction kinetics. Benefiting from the synergy between structural and electronic modulation, the catalyst shows excellent activity toward water oxidation under alkaline conditions: overpotential of 200 mV at 10 mA/cm(2) current density and Tafel slope of 28 mV/dec. This work opens up a new window for understanding the structure-activity relationship of OER catalysts and encourages new strategies for development of more advanced OER catalysts.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-241005 (URN)10.1021/acsenergylett.8b01897 (DOI)000453805100003 ()2-s2.0-85056263175 (Scopus ID)
Note

QC 20190109

Available from: 2019-01-09 Created: 2019-01-09 Last updated: 2019-08-20Bibliographically approved
Zhang, J., Daniel, Q., Zhang, T., Wen, X., Xu, B., Sun, L., . . . Cheng, Y.-B. (2018). Chemical Dopant Engineering in Hole Transport Layers for Efficient Perovskite Solar Cells: Insight into the Interfacial Recombination. ACS Nano, 12(10), 10452-10462
Open this publication in new window or tab >>Chemical Dopant Engineering in Hole Transport Layers for Efficient Perovskite Solar Cells: Insight into the Interfacial Recombination
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2018 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 10, p. 10452-10462Article in journal (Refereed) Published
Abstract [en]

Chemical doping of organic semiconductors has been recognized as an effective way to enhance the electrical conductivity. In perovskite solar cells (PSCs), various types of dopants have been developed for organic hole transport materials (HTMs); however, the knowledge of the basic requirements for being efficient dopants as well as the comprehensive roles of the dopants in PSCs has not been clearly revealed. Here, three copper-based complexes with controlled redox activities are applied as dopants in PSCs, and it is found that the oxidative reactivity of dopants presents substantial impacts on conductivity, charge dynamics, and solar cell performance. A significant improvement of open- circuit voltage (V-oc) by more than 100 mV and an increase of power conversion efficiency from 13.2 to 19.3% have been achieved by tuning the doping level of the HTM. The observed large variation of V-oc for three dopants reveals their different recombination kinetics at the perovskite/HTM interfaces and suggests a model of an interfacial recombination mechanism. We also suggest that the dopants in HTMs can also affect the charge recombination kinetics as well as the solar cell performance. Based on these findings, a strategy is proposed to physically passivate the electron- hole recombination by inserting an ultrathin Al2O3 insulating layer between the perovskite and the HTM. This strategy contributes a significant enhancement of the power conversion efficiency and environmental stability, indicating that dopant engineering is one crucial way to further improve the performance of PSCs.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
chemical dopants, hole transport materials, perovskite solar cells, interfacial recombination, passivation, Al2O3
National Category
Other Engineering and Technologies
Identifiers
urn:nbn:se:kth:diva-239110 (URN)10.1021/acsnano.8b06062 (DOI)000448751800083 ()30207694 (PubMedID)2-s2.0-85053682102 (Scopus ID)
Note

QC 20181121

Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2019-08-20Bibliographically approved
Sharmoukh, W., Cong, J., Gao, J., Liu, P., Quentin, D. & Kloo, L. (2018). Molecular Engineering of D-D-pi-A-Based Organic Sensitizers for Enhanced Dye-Sensitized Solar Cell Performance. ACS OMEGA, 3(4), 3819-3829
Open this publication in new window or tab >>Molecular Engineering of D-D-pi-A-Based Organic Sensitizers for Enhanced Dye-Sensitized Solar Cell Performance
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2018 (English)In: ACS OMEGA, ISSN 2470-1343, Vol. 3, no 4, p. 3819-3829Article in journal (Refereed) Published
Abstract [en]

A series of molecularly engineered and novel dyes WS1, WS2, WS3, and WS4, based on the D35 donor, 1-(4-hexylphenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole and 4-(4-hexylphenyl)-4H-dithieno[3,2-b: 2', 3'-d] pyrrole as pi-conjugating linkers, were synthesized and compared to the well-known LEG4 dye. The performance of the dyes was investigated in combination with an electrolyte based on Co(II/III) complexes as redox shuttles. The electron recombination between the redox mediators in the electrolyte and the TiO2 interface decreases upon the introduction of 4-hexylybenzene entities on the 2,5-di(thiophen-2-yl)-1H-pyrrole and 4H-dithieno[3,2-b: 2', 3'-d] pyrrole linker units, probably because of steric hindrance. The open circuit photovoltage of WS1-, WS2-, WS3-, and WS4-based devices in combination with the Co(II/III)-based electrolyte are consistently higher than those based on a I-/I-3(-) electrolyte by 105, 147, 167, and 75 mV, respectively. The WS3-based devices show the highest power conversion efficiency of 7.4% at AM 1.5 G 100 mW/cm(2) illumination mainly attributable to the high open-circuit voltage (V-OC).

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-227229 (URN)10.1021/acsomega.8b00271 (DOI)000430200300022 ()2-s2.0-85045042845 (Scopus ID)
Note

QC 20150514

Available from: 2018-05-14 Created: 2018-05-14 Last updated: 2018-05-14Bibliographically approved
Fan, T., Duan, L., Huang, P., Chen, H., Daniel, Q., Ahlquist, M. S. G. & Sun, L. (2017). The Ru-tpc Water Oxidation Catalyst and Beyond: Water Nucleophilic Attack Pathway versus Radical Coupling Pathway.. ACS Catalysis, 7(4), 2956-2966
Open this publication in new window or tab >>The Ru-tpc Water Oxidation Catalyst and Beyond: Water Nucleophilic Attack Pathway versus Radical Coupling Pathway.
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2017 (English)In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 7, no 4, p. 2956-2966Article in journal (Refereed) Published
Abstract [en]

Many Ru water oxidation catalysts have been documented in the literature. However, only a few can catalyze the O-O bond formation via the radical coupling pathway, while most go through the water nucleophilic attack pathway. Understanding the electronic effect on the reaction pathway is of importance in design of active water oxidation catalysts. The Ru-bda (bda = 2,2'-bipyridine-6,6'-dicarboxylate) catalyst is one example that catalyzes the 0-0 bond formation via the radical coupling pathway. Herein, we manipulate the equatorial backbone ligand, change the doubly charged bda(2-) ligand to a singly charged tpc- (2,2':6',2 ''-terpyridine-6-carboxylate) ligand, and study the structure activity relationship. Surprisingly, kinetics measurements revealed that the resulting Ru-tpc catalyst catalyzes water oxidation via the water nucleophilic attack pathway, which is different from the Ru-bda catalyst. The O-O bond formation Gibbs free energy of activation (AGO) at T = 298.15 K was 20.2 +/- 1.7 kcal mol(-1). The electronic structures of a series of Ru-v=O species were studied by density function theory calculations, revealing that the spin density of O-Ru=O of Ru-v=O is largely dependent on the surrounding ligands. Seven coordination configuration significantly enhances the radical character of Ru-v=O.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
Keywords
water oxidation, ruthenium complex, artificial photosynthesis, DFT calculation, water splitting
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-206688 (URN)10.1021/acscatal.6b03393 (DOI)000398986700082 ()
Note

QC 20170509

Available from: 2017-05-09 Created: 2017-05-09 Last updated: 2017-05-09Bibliographically approved
Wang, L., Fan, K., Chen, H., Daniel, Q., Philippe, B., Rensmo, H. & Sun, L. (2017). Towards efficient and robust anodes for water splitting: Immobilization of Ru catalysts on carbon electrode and hematite by in situ polymerization. Catalysis Today, 290, 73-77
Open this publication in new window or tab >>Towards efficient and robust anodes for water splitting: Immobilization of Ru catalysts on carbon electrode and hematite by in situ polymerization
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2017 (English)In: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 290, p. 73-77Article in journal (Refereed) Published
Abstract [en]

Ru-bda based molecular water oxidation catalysts 1 and 2 (H(2)bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) containing a thiophene group are attached to the surfaces of electrodes by the method of electropolymerization. The Ru-bda molecular catalyst functionalized graphite carbon electrode can catalyze water oxidation efficiently under a overpotential of ca 500 mV to obtain current density of 5 mA cm(-2); and the similarly functionalized photoelectrode based on alpha-Fe2O3 (hematite) film can work as an photoanode for light driven water splitting.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2017
Keywords
Water oxidation, Electrochemistry, Molecular catalyst, Polymerization, alpha-Fe2O3
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-210455 (URN)10.1016/j.cattod.2016.07.011 (DOI)000402706700011 ()2-s2.0-85008391610 (Scopus ID)
Funder
Swedish Research CouncilKnut and Alice Wallenberg FoundationSwedish Energy Agency
Note

QC 20170706

Available from: 2017-07-06 Created: 2017-07-06 Last updated: 2017-10-09Bibliographically approved
Cong, J., Kinschel, D., Daniel, Q., Safdari, M., Gabrielsson, E., Chen, H., . . . Kloo, L. (2016). Bis(1,1-bis(2-pyridyl)ethane)copper(i/II) as an efficient redox couple for liquid dye-sensitized solar cells. Journal of Materials Chemistry A, 4(38), 14550-14554
Open this publication in new window or tab >>Bis(1,1-bis(2-pyridyl)ethane)copper(i/II) as an efficient redox couple for liquid dye-sensitized solar cells
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2016 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 38, p. 14550-14554Article in journal (Refereed) Published
Abstract [en]

A new redox couple, [Cu(bpye)2]+/2+, has been synthesized, and applied in dye-sensitized solar cells (DSSCs). Overall efficiencies of 9.0% at 1 sun and 9.9% at 0.5 sun were obtained, which are considerably higher than those obtained for cells containing the reference redox couple, [Co(bpy)3]2+/3+. These results represent a record for copper-based complex redox systems in liquid DSSCs. Fast dye regeneration, sluggish recombination loss processes, faster electron self-exchange reactions and suitable redox potentials are the main reasons for the observed increase in efficiency. In particular, the main disadvantage of cobalt complex-based redox couples, charge-transport problems, appears to be resolved by a change to copper complex redox couples. The results make copper complex-based redox couples very promising for further development of highly efficient DSSCs.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016
Keywords
Cobalt compounds, Copper, Efficiency, Redox reactions, Solar cells, Cobalt complexes, Copper complexes, Dye regeneration, Electron self-exchange, Overall efficiency, Recombination loss, Redox potentials, Transport problems, Dye-sensitized solar cells
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-195535 (URN)10.1039/c6ta06782d (DOI)000385360300005 ()2-s2.0-84989315761 (Scopus ID)
Funder
Swedish Research Council Formas
Note

QC 20161115

Available from: 2016-11-15 Created: 2016-11-03 Last updated: 2017-11-29Bibliographically approved
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