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Bayrak Pehlivan, Ilknur
Alternative names
Publications (10 of 32) Show all publications
Pati, P. B., Damas, G., Tian, L., Fernandes, D. L. A., Zhang, L., Bayrak Pehlivan, I., . . . Tian, H. (2017). An experimental and theoretical study of an efficient polymer nano-photocatalyst for hydrogen evolution. Energy & Environmental Science, 10(6), 1372-1376.
Open this publication in new window or tab >>An experimental and theoretical study of an efficient polymer nano-photocatalyst for hydrogen evolution
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2017 (English)In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 10, no 6, 1372-1376 p.Article in journal (Refereed) Published
Abstract [en]

In this work, we report a highly efficient organic polymer nano-photocatalyst for light driven proton reduction. The system renders an initial rate of hydrogen evolution up to 50 +/- 0.5 mmol g(-1) h(-1), which is the fastest rate among all other reported organic photocatalysts. We also experimentally and theoretically prove that the nitrogen centre of the benzothiadiazole unit plays a crucial role in the photocatalysis and that the Pdots structure holds a close to ideal geometry to enhance the photocatalysis.

Keyword
CATALYSTS; H-2; SYSTEM; ENVIRONMENTAL SCIENCES; CELLS; CONJUGATED POLYMERS; ENERGY & FUELS; ARTIFICIAL PHOTOSYNTHESIS; WATER; ENGINEERING, CHEMICAL; GENERATION; CHEMISTRY, MULTIDISCIPLINARY; VISIBLE-LIGHT
National Category
Polymer Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-332949 (URN)DOI: 10.1039/c7ee00751e (DOI)
Funder
Knut and Alice Wallenberg Foundation
Available from: 2017-11-02 Created: 2017-11-02 Last updated: 2017-11-13
Bayrak Pehlivan, I., Marsal, R., Pehlivan, E., Runnerstrom, E. L., Milliron, D. J., Granqvist, C.-G. & Niklasson, G. (2014). Electrochromic Devices with Polymer Electrolytes Functionalized by SiO2 and In2O3:Sn Nanoparticles: Rapid Coloration/Bleaching Dynamics and Strong Near-Infrared Absorption. Solar Energy Materials and Solar Cells, 126, 241-247.
Open this publication in new window or tab >>Electrochromic Devices with Polymer Electrolytes Functionalized by SiO2 and In2O3:Sn Nanoparticles: Rapid Coloration/Bleaching Dynamics and Strong Near-Infrared Absorption
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2014 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 126, 241-247 p.Article in journal (Refereed) Published
National Category
Engineering and Technology Nano Technology
Identifiers
urn:nbn:se:uu:diva-284199 (URN)
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2017-11-30
Pehlivan, I. B., Marsal, R., Pehlivan, E., Runnerstrom, E. L., Milliron, D. J., Granqvist, C.-G. & Niklasson, G. A. (2014). Electrochromic Devices with Polymer Electrolytes Functionalized by SiO2 and In2O3:Sn Nanoparticles: Rapid Coloring/Bleaching Dynamics and Strong Near-Infrared Absorption. Paper presented at 10th International Meeting on Electrochromism (IME), Holland, MI, August 12-16, 2012. Solar Energy Materials and Solar Cells, 126, 241-247.
Open this publication in new window or tab >>Electrochromic Devices with Polymer Electrolytes Functionalized by SiO2 and In2O3:Sn Nanoparticles: Rapid Coloring/Bleaching Dynamics and Strong Near-Infrared Absorption
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2014 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 126, 241-247 p.Article in journal (Refereed) Published
Abstract [en]

We studied the optical properties and coloring/bleaching dynamics of electrochromic devices based on tungsten oxide and nickel oxide and incorporating polymer electrolytes functionalized by adding about one percent of nanoparticles of SiO2 (fumed silica) or In2O3:Sn. SiO2 improved the coloring/bleaching dynamics and In2O3:Sn quenched the near-infrared transmittance. Both of these effects can be important in electrochromic smart windows, and our results point at the advantage of a polymer laminated construction over a monolithic one.

National Category
Nano Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-204448 (URN)10.1016/j.solmat.2013.06.010 (DOI)000338395100035 ()
Conference
10th International Meeting on Electrochromism (IME), Holland, MI, August 12-16, 2012
Available from: 2013-08-05 Created: 2013-08-05 Last updated: 2017-12-06Bibliographically approved
Granqvist, C.-G., Bayrak Pehlivan, I., Ji, Y.-X. -., Li, S.-Y. & Niklasson, G. A. (2014). Electrochromics and thermochromics for energy efficient fenestration: Functionalities based on nanoparticles of In2O3:Sn and VO2. Thin Solid Films, 559, 2-8.
Open this publication in new window or tab >>Electrochromics and thermochromics for energy efficient fenestration: Functionalities based on nanoparticles of In2O3:Sn and VO2
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2014 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 559, 2-8 p.Article in journal (Refereed) Published
Abstract [en]

Windows incorporating electrochromic (EC) and thermochromic (TC) materials are of great interest for today's and tomorrow's buildings and can create energy efficiency jointly with indoor comfort. This paper summarizes several recent studies and shows that nanoparticles of transparent conducting oxides-specifically In2O3: Sn (ITO) and thermochromic VO2-can lead to desirable functionalities. We consider three examples: (i) the use of ITO nanoparticles in conventional polaronic EC devices in order to suppress near-infrared solar transmittance, (ii) performance limits for plasmonic EC devices based on ITO nanoparticles, and (iii) ITO-VO2-based nanocomposites combining low thermal emittance with TC properties. We also consider Mg doping of VO2 to enhance the luminous transmittance and Al2O3/VO2 double layers with improved durability. Both experimental and theoretical results are reported. (C) 2013 Elsevier B. V. All rights reserved.

Keyword
Electrochromism, Thermochromism, Smart window, Energy efficiency, Nanoparticles, Indium tin oxide, Vanadium dioxide
National Category
Physical Sciences Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-227175 (URN)10.1016/j.tsf.2013.10.033 (DOI)000335443500002 ()
Projects
EU GRINDOOR
Funder
EU, FP7, Seventh Framework Programme, 267234
Available from: 2014-06-27 Created: 2014-06-24 Last updated: 2017-12-05Bibliographically approved
Bayrak Pehlivan, I., Granqvist, C.-G. & Niklasson, G. A. (2014). Ion conduction mechanism of nanocomposite polymer electrolytes comprised of polyethyleneimine–lithium bis(trifluoromethylsulfonyl)imide and silica. Electrochimica Acta, 119, 164-168.
Open this publication in new window or tab >>Ion conduction mechanism of nanocomposite polymer electrolytes comprised of polyethyleneimine–lithium bis(trifluoromethylsulfonyl)imide and silica
2014 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 119, 164-168 p.Article in journal (Refereed) Published
National Category
Nano Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-204451 (URN)10.1016/j.electacta.2013.12.032 (DOI)000335877000023 ()
Available from: 2013-08-05 Created: 2013-08-05 Last updated: 2017-12-06Bibliographically approved
Granqvist, C.-G., Bayrak Pehlivan, I., Ji, Y.-X., Li, S.-Y., Marsal, R. & Niklasson, G. (2013). Electrochromics and Thermochromics for Energy Efficient Fenestration: New Applications Based on Transparent Conducting Nanoparticles. MRS Proceedings Library, 1-12, Article ID mrs13-1558-z09.
Open this publication in new window or tab >>Electrochromics and Thermochromics for Energy Efficient Fenestration: New Applications Based on Transparent Conducting Nanoparticles
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2013 (English)In: MRS Proceedings Library, 1-12 p., mrs13-1558-z09Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-284215 (URN)
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2016-04-21
Granqvist, C.-G., Bayrak Pehlivan, I., Ji, Y.- . X., Li, S.-Y., Pehlivan, E., Marsal, R. & Niklasson, G. (2013). Electrochromics and Thermochromics for Energy Efficient Fenestration: New Applications Based on Transparent Conducting Nanoparticles. Materials Research Society Symposium Proceedings, 1558, 12 p., Article ID mrs13-1558-z09.
Open this publication in new window or tab >>Electrochromics and Thermochromics for Energy Efficient Fenestration: New Applications Based on Transparent Conducting Nanoparticles
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2013 (English)In: Materials Research Society Symposium Proceedings, ISSN 0272-9172, E-ISSN 1946-4274, Online Library, Vol. 1558, 12 p.- p., mrs13-1558-z09Article in journal (Refereed) Published
National Category
Engineering and Technology Nano Technology
Identifiers
urn:nbn:se:uu:diva-285231 (URN)
Available from: 2016-04-19 Created: 2016-04-19 Last updated: 2017-11-30
Bayrak Pehlivan, İ. (2013). Functionalization of polymer electrolytes for electrochromic windows. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis.
Open this publication in new window or tab >>Functionalization of polymer electrolytes for electrochromic windows
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Saving energy in buildings is of great importance because about 30 to 40 % of the energy in the world is used in buildings. An electrochromic window (ECW), which makes it possible to regulate the inflow of visible light and solar energy into buildings, is a promising technology providing a reduction in energy consumption in buildings along with indoor comfort. A polymer electrolyte is positioned at the center of multi-layer structure of an ECW and plays a significant role in the working of the ECW.

In this study, polyethyleneimine: lithium (bis(trifluoromethane)sulfonimide (PEI:LiTFSI)-based polymer electrolytes were characterized by using dielectric/impedance spectroscopy, differential scanning calorimetry, viscosity recording, optical spectroscopy, and electrochromic measurements.

In the first part of the study, PEI:LiTFSI electrolytes were characterized at various salt concentrations and temperatures. Temperature dependence of viscosity and ionic conductivity of the electrolytes followed Arrhenius behavior. The viscosity was modeled by the Bingham plastic equation. Molar conductivity, glass transition temperature, viscosity, Walden product, and iso-viscosity conductivity analysis showed effects of segmental flexibility, ion pairs, and mobility on the conductivity. A connection between ionic conductivity and ion-pair relaxation was seen by means of (i) the Barton-Nakajima-Namikawa relation, (ii) activation energies of the bulk relaxation, and ionic conduction and (iii) comparing two equivalent circuit models, containing different types of Havriliak-Negami elements, for the bulk response.

In the second part, nanocomposite PEI:LiTFSI electrolytes with SiO2, In2O3, and In2O3:Sn (ITO) were examined. Adding SiO2 to the PEI:LiTFSI enhanced the ionic conductivity by an order of magnitude without any degradation of the optical properties. The effect of segmental flexibility and free ion concentration on the conduction in the presence of SiO2 is discussed. The PEI:LiTFSI:ITO electrolytes had high haze-free luminous transmittance and strong near-infrared absorption without diminished ionic conductivity. Ionic conductivity and optical clarity did not deteriorate for the PEI:LiTFSI:In2O3 and the PEI:LiTFSI:SiO2:ITO electrolytes.

Finally, propylene carbonate (PC) and ethylene carbonate (EC) were added to PEI:LiTFSI in order to perform electrochromic measurements. ITO and SiO2 were added to the PEI:LiTFSI:PC:EC and to a proprietary electrolyte. The nanocomposite electrolytes were tested for ECWs with the configuration of the ECWs being plastic/ITO/WO3/polymer electrolyte/NiO (or IrO2)/ITO/plastic. It was seen that adding nanoparticles to polymer electrolytes can improve the coloring/bleaching dynamics of the ECWs.

From this study, we show that nanocomposite polymer electrolytes can add new functionalities as well as enhancement in ECW applications.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2013. 172 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1057
Keyword
Electrochromism, Polymer electrolytes, PEI, LiTFSI, Nanoparticles, Ionic conductivity, Ion-pair relaxation, Near-infrared absorption
National Category
Nano Technology Composite Science and Engineering Textile, Rubber and Polymeric Materials
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-204437 (URN)978-91-554-8714-0 (ISBN)
Public defence
2013-09-20, Polhemsalen, Ångström Laboratory, Lägerhyddsvägen 1, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2013-08-30 Created: 2013-08-05 Last updated: 2014-01-07
Granqvist, C.-G., Li, S.-Y., Bayrak Pehlivan, I. & Niklasson, G. (2013). Progress in chromogenic materials and devices: New data on electrochromics and thermochromics. Materials Research Society Symposium Proceedings, 1492, 99-110.
Open this publication in new window or tab >>Progress in chromogenic materials and devices: New data on electrochromics and thermochromics
2013 (English)In: Materials Research Society Symposium Proceedings, ISSN 0272-9172, E-ISSN 1946-4274, Vol. 1492, 99-110 p.Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-285228 (URN)
Available from: 2016-04-19 Created: 2016-04-19 Last updated: 2017-11-30
Granqvist, C.-G., Bayrak Pehlivan, I., Ji, Y.-X., Li, S.-Y. & Niklasson, G. (2013). Transparent Conducting Nanoparticle Coatings for Energy Efficient Fenestration: Applications in Electrochromics and Thermochromics. In: Soc. Vacuum Coaters 56th Ann. Techn. Conf. Proc.: . Paper presented at Soc. Vacuum Coaters 56th Ann. Techn. Conf. Proc., 2013, Albuquerque, USA. .
Open this publication in new window or tab >>Transparent Conducting Nanoparticle Coatings for Energy Efficient Fenestration: Applications in Electrochromics and Thermochromics
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2013 (English)In: Soc. Vacuum Coaters 56th Ann. Techn. Conf. Proc., 2013Conference paper, Published paper (Refereed)
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-284226 (URN)
Conference
Soc. Vacuum Coaters 56th Ann. Techn. Conf. Proc., 2013, Albuquerque, USA
Available from: 2016-04-15 Created: 2016-04-15 Last updated: 2016-04-21
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