| 1. |
- Dürr, Robin N., et al.
(author)
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Efficient, Stable, and Solvent-Free Synthesized Single-Atom Catalysts : Carbonized Transition Metal-Doped ZIF-8 for the Hydrogen Evolution Reaction
- 2023
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In: ChemElectroChem. - : Wiley-VCH Verlagsgesellschaft. - 2196-0216. ; 10:14
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Journal article (peer-reviewed)abstract
- Herein we present non-noble metal single-atom catalysts (SACs) based on carbonized transition metal-doped zeolitic imidazolate frameworks (ZIFs) as stable and efficient electrocatalysts for the hydrogen evolution reaction in acidic media. In this work, earth-abundant metals are embedded in a porous N-rich carbon matrix by pyrolyzing metal-doped ZIF structures and characterized by spectroscopic, microscopic, and electrochemical methods. The complete synthesis of these high surface area SACs was carried out without any solvents and hence offers a promising route for a more sustainable catalyst production and industrial upscaling. As the best-performing catalyst, cobalt SAC illustrated already with a low cobalt loading of <0.3 at.% a substantial increase in activity with an overpotential of -322 mV for -10 mA cm(-2), and high stability during electrolysis at -10 mA cm(-2) for 12 h in acidic media, with only a small decrease of 33 mV to more negative potentials after the initiation period.
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| 3. |
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| 4. |
- Gadisa, Abay, et al.
(author)
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Stoichiometry dependence of charge transport in polymer/methanofullerene and polymer/C70 derivative based solar cells
- 2006
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In: Organic electronics. - : Elsevier BV. - 1566-1199. ; 7:4, s. 195-204
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Journal article (peer-reviewed)abstract
- Charge transport in a near infrared absorbing polyfluorene copolymer (APFO-Green1) and its blends with methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and 3′-(3,5-bis-trifluoromethylphenyl)-1′-(4-nitrophenyl)pyrazolino[70]fullerene (BTPF70) is reported. PCBM and BTPF70 are electron acceptor and transporting molecules in polymer based solar cells. The BTPF70 has emerged as a new electron acceptor molecule that provides adequate exciton dissociation when blended with the low band gap polyfluorene copolymer APFO-Green1. Electron transport in both net PCBM and BTPF70 films are subjected to positional and energetic disorder, with the degree of disorder being more pronounced in BTPF70. On the other hand, mixing PCBM with conjugated polymers usually leads to increased hole mobility. We have investigated and compared the acceptor concentration dependence of charge transport in APFO-Green1/PCBM and APFO-Green1/BTPF70 blend films. For better understanding of the charge transport in the heterojunction films, the field and temperature dependence of hole transport in pure APFO-Green1 films has also been studied. It is observed that the behavior of hole mobility in the blend layer is sensitive to the acceptor type. For APFO-Green1/PCBM hole only devices, the hole mobility attains a local maximum at 67 wt.% of PCBM, while on the contrary mixing any amount of BTPF70 with APFO-Green1 results into degradation of hole transport. Electron transport in both blends, however, increases monotonically as a function of acceptor loading.
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| 5. |
- Gadisa, Abay, et al.
(author)
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Stoichiometry dependence of charge transport in polymer/methanofullerene and polymer/C70 derivative based solar cells
- 2006
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In: Organic Electronics. ; 7:4, s. 195-204
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Journal article (peer-reviewed)abstract
- Charge transport in a near IR absorbing polyfluorene copolymer (APFO-Green1) and its blends with methanofullerene [6,6]-Ph C61-butyric acid Me ester (PCBM), and 3'-(3,5-bis-trifluoromethylphenyl)-1'-(4-nitrophenyl)pyrazolino[70]fullerene (BTPF70) is reported. PCBM and BTPF70 are electron acceptor and transporting mols. in polymer based solar cells. The BTPF70 has emerged as a new electron acceptor mol. that provides adequate exciton dissocn. when blended with the low band gap polyfluorene copolymer APFO-Green1. Electron transport in both net PCBM and BTPF70 films are subjected to positional and energetic disorder, with the degree of disorder being more pronounced in BTPF70. On the other hand, mixing PCBM with conjugated polymers usually leads to increased hole mobility. We have investigated and compared the acceptor concn. dependence of charge transport in APFO-Green1/PCBM and APFO-Green1/BTPF70 blend films. For better understanding of the charge transport in the heterojunction films, the field and temp. dependence of hole transport in pure APFO-Green1 films has also been studied. It is obsd. that the behavior of hole mobility in the blend layer is sensitive to the acceptor type. For APFO-Green1/PCBM hole only devices, the hole mobility attains a local max. at 67 wt.% of PCBM, while on the contrary mixing any amt. of BTPF70 with APFO-Green1 results into degrdn. of hole transport. Electron transport in both blends, however, increases monotonically as a function of acceptor loading. [on SciFinder (R)]
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| 6. |
- Wang, Xiangjun, et al.
(author)
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Enhanced photocurrent spectral response in low-bandgap polyfluorene and C70-Derivative-Based Solar Cells
- 2005
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In: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 15:10, s. 1665-1670
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Journal article (peer-reviewed)abstract
- Plastic solar cells have been fabricated using a low-bandgap alternating copolymer of fluorene and a donor-acceptor-donor moiety (APFO-Green1), blended with 3-(3,5-bis-trifluoromethylphenyl)-1-(4-nitrophenyl)pyrazolino[70]fullerene (BTPF70) as electron acceptor. The polymer shows optical absorption in two wavelength ranges, < 500 nm and 600 < < 1000 nm. The BTPF70 absorbs light at < 700 nm. A broad photocurrent spectral response in the wavelength range 300 < < 1000 nm is obtained in solar cells. A photocurrent density of 3.4 mA cm-2, open-circuit voltage of 0.58 V, and power-conversion efficiency of 0.7 % are achieved under illumination of AM1.5 (1000 W m-2) from a solar simulator. Synthesis of BTPF70 is presented. Photoluminescence quenching and electrochemical studies are used to discuss photoinduced charge transfer.
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| 7. |
- Wang, Xiangjun, et al.
(author)
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Enhanced photocurrent spectral response in low-bandgap polyfluorene and C70-derivative-based solar cells
- 2005
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In: Advanced Functional Materials. ; 15:10, s. 1665-1670
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Journal article (peer-reviewed)abstract
- Plastic solar cells have been fabricated using a low-bandgap alternating copolymer of fluorene and a donor-acceptor-donor moiety (APFO-Green1), blended with 3'-(3,5-bis-trifluoromethylphenyl)-1'-(4-nitrophenyl)pyrazolino fullerene (BTPF70) as electron acceptor. The polymer shows optical absorption in two wavelength ranges, l
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| 8. |
- Wang, Xiangjun, et al.
(author)
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Polymer solar cells with low-bandgap polymers blended with C70-derivative give photocurrent at 1 μm
- 2006
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In: Thin Solid Films. - : Elsevier BV. - 0040-6090. ; 511-512, s. 576-580
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Journal article (peer-reviewed)abstract
- A new series of low-bandgap alternating polyfluorenes with different donor–acceptor–donor moieties have been synthesized. Electrochemical and optical absorption measurement show that onset bandgaps of these polymers range from 1.2 to 1.5 eV. These polymers, blended with a C70-derivative as acceptor, are used for solar cell fabrication. Devices show promising photovoltaic properties, and the spectral response of photocurrent covers all visible and near-infrared wavelength regions with its onset extended to 1 μm. The best data gives a photocurrent density of 3.4 mA/cm2, open circuit voltage of 0.58 V and power conversion efficiency of 0.7% under illumination of AM1.5 (1000 W/m2) from a solar simulator.
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| 9. |
- Wood, Christopher J., et al.
(author)
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A comprehensive comparison of dye-sensitized NiO photocathodes for solar energy conversion
- 2016
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In: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 18:16, s. 10727-10738
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Journal article (peer-reviewed)abstract
- We investigated a range of different mesoporous NiO electrodes prepared by different research groups and private firms in Europe to determine the parameters which influence good quality photoelectrochemical devices. This benchmarking study aims to solve some of the discrepancies in the literature regarding the performance of p-DSCs due to differences in the quality of the device fabrication. The information obtained will lay the foundation for future photocatalytic systems based on sensitized NiO so that new dyes and catalysts can be tested with a standardized material. The textural and electrochemical properties of the semiconducting material are key to the performance of photocathodes. We found that both commercial and non-commercial NiO gave promising solar cell and water-splitting devices. The NiO samples which had the two highest solar cell efficiency (0.145% and 0.089%) also gave the best overall theoretical H-2 conversion.
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