| 1. |
- Luo, Jiaxin, et al.
(författare)
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Solar cells sensitized by donor-linked concerted companion dyes
- 2023
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 11:16, s. 5450-5460
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Tidskriftsartikel (refereegranskat)abstract
- Recently, concerted companion (CC) dyes have been developed by covalently linking the acceptors of organic and porphyrin dye units. Herein, a new class of CC dyes XW85 and XW86 have been designed by linking the donors of porphyrin and organic dye units with C6H12 and C12H24 chains, respectively. The DSSCs of XW85 based on the I-3(-)/I- electrolyte show significant J(SC) (17.20 mA cm(-2)) and PCE (8.96%), and XW86 exhibits higher J(SC) (18.55 mA cm(-2)) and PCE (9.76%), which are also higher than those of the corresponding cosensitization systems. However, the PCEs for XW85 and XW86 are lower than that of the acceptor-linked reference dye XW76 despite the obviously larger dye adsorption amounts. Desorption studies reveal that the CC dyes may be either double-anchored or single-anchored, with the double/single anchoring ratios lying in a sequence of XW85 (1.31) < XW86 (1.88) < XW76 (6.34), consistent with that of increasing PCE. These observations indicate that the non-adsorbed sub-dye unit cannot effectively contribute to electron injection, and thus relatively large mono-anchoring proportions for XW85 and XW86 result in their relatively low J(SC), and the difference between XW85 and XW86 indicates that a longer linking chain is beneficial for partially alleviating the unfavorable single anchoring, resulting in superior performance. The results indicate that the photovoltaic behavior for the CC dyes may be further enhanced by avoiding the unfavorable alignment of the two carboxyl groups in opposite directions and thus simultaneously anchoring the two carboxyl groups, which may be realized through more rational molecular design.
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| 2. |
- Zou, Jiazhi, et al.
(författare)
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Efficient Dye-Sensitized Solar Cells Based on a New Class of Doubly Concerted Companion Dyes
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:29, s. 33274-33284
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Tidskriftsartikel (refereegranskat)abstract
- To develop efficient dye-sensitized solar cells (DSSCs), concerted companion (CC) dyes XW60-XW63 constructed from the covalent linkage of a strapped porphyrin dye unit and an organic dye unit have been reported to exhibit panchromatic absorption and excellent photovoltaic performance. However, these CC dyes only afforded moderate V-OC values of ca. 763 mV, demonstrating relatively weak antiaggregation ability, which remains an obstacle for further enhancing the photovoltaic behavior. To address this problem, we herein develop porphyrin dyes XW77-XW80 with the macrocycles wrapped with alkoxy chains of various lengths (OC6H13-OC22H45) and the corresponding CC dyes XW81-XW84 containing these porphyrin dye units. Interestingly, the new CC dyes XW81-XW83 exhibit increasing V-OC from 745 to 784 mV with the chain lengths extended from C6 to C18, and a lowered V-OC of 762 mV was obtained for XW84 when the chain length was further extended to C22. As a result, XW83 afforded the highest PCE of 12.2%, which is, to the best of our knowledge, the record efficiency for the iodine electrolyte-based solar cells sensitized with a single dye. These results can be rationalized by the so-called doubly concerted companion (DCC) effects, that is, the two subdye units exhibit not only complementary absorption but also concerted antiaggregation with the long wrapping chains on the porphyrins unit simultaneously protecting the porphyrin macrocycle and the neighboring organic subdye unit, thus affording panchromatic absorption and strong antiaggregation and anticharge-recombination ability. These results provide a new approach for constructing a class of DCC dyes to achieve high-performance DSSCs without using any antiaggregating coadsorbent or absorption-enhancing cosensitizer.
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| 3. |
- Fu, Xianbiao, et al.
(författare)
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High-Entropy Alloy Nanosheets for Fine-Tuning Hydrogen Evolution
- 2022
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 12:19, s. 11955-11959
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Tidskriftsartikel (refereegranskat)abstract
- The electrolysis of water is promising for hydrogen production. The development of high-performance and low-cost hydrogen evolution reaction (HER) electrocatalysts is particularly important for the wide application of water electrolyzers. Tuning the hydrogen binding energy (HBE) of materials is an effective way to optimize the HER electrocatalysts, particularly for applications in an acidic environment. Here, we report the discovery of a Pt-free combination, PdMoGaInNi, which has the HBE optimum, via computer-facilitated screening. As the exploratory example of the two-dimensional high-entropy alloy (HEA) for HER, the PdMoGaInNi HEA nanosheets were synthesized to realize the predicted Pt-free combination with optimal HBE. The PdMoGaInNi HEA nanosheets exhibit a high HER activity with low overpotentials of 13 mV at 10 mA cm-2, outperforming commercial Pd/C and Pt/C catalysts. Given the high entropy, lattice distortion, and sluggish diffusion effects of HEA, the PdMoGaInNi shows great long-term durability for at least 200 h in a proton exchange membrane water electrolyzer.
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| 4. |
- He, Yixing, et al.
(författare)
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Chain Length Modulated Dimerization and Cyclization of Terminal Thienyl-Blocked Oligopyrranes
- 2022
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Ingår i: Organic Letters. - : AMER CHEMICAL SOC. - 1523-7060 .- 1523-7052. ; 24:29, s. 5428-5432
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Tidskriftsartikel (refereegranskat)abstract
- Oxidation of thienyl-blocked bilane and pentapyrrane afforded chain length dependent products of the symmetric dimer D1 and the thienyloligopyrrin-appended pentaphyrin analogue P2, respectively, with the latter formed by simultaneous dimerization and cyclization. Coordination of D1 and P2 with Cu(II) afforded di-and monometallic complexes D1-Cu2 and P2 -Cu, respectively. These compounds exhibit distinct NIR absorption, with the absorption tail of D1-Cu2 extended to ca. 1900 nm despite its smaller conjugation framework than that of P2 -Cu.
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| 5. |
- Li, Qizhao, et al.
(författare)
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Antiaromatic Sapphyrin Isomer : Transformation into Contracted Porphyrinoids with Variable Aromaticity
- 2023
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Ingår i: Angewandte Chemie International Edition. - : Wiley-VCH Verlagsgesellschaft. - 1433-7851 .- 1521-3773. ; 62:1
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Tidskriftsartikel (refereegranskat)abstract
- Sapphyrin is a pentapyrrolic expanded porphyrin with a 22π aromatic character. Herein, we report the synthesis of a 20π antiaromatic sapphyrin isomer 1 by oxidative cyclization of a pentapyrrane precursor P5 with a terminal β-linked pyrrole. The resulting isomer 1, containing a mis-linked bipyrrole unit in the skeleton, exhibits a reactivity for further oxidation due to the distinct antiaromatic electronic structure, affording a fused macrocycle 2, possessing a spiro-carbon-containing [5.6.5.6]-tetracyclic structure. Subsequent treatment with an acid afforded a weakly aromatic pyrrolone-appended N-confused corrole 3, and thermal fusion gave a [5.6.5.7]-tetracyclic-ring-embedded 14π aromatic triphyrin(2.1.1) analog 4. The cyclization at the mis-linked pyrrole moiety of P5 played a crucial role in synthesizing the antiaromatic porphyrinoid susceptible to facile transformation to novel porphyrinoids with variable aromaticity.
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| 6. |
- Lu, P. F., et al.
(författare)
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A theoretical investigation on thermoelectric performance of ternary (Bi1-xSbx)(2)Te-3 compound
- 2013
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 48:14, s. 4999-5004
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structure and thermoelectric properties of (Bi1-x Sb (x) )(2)Te-3 compound are investigated by using full-potential linearized augmented plane-wave method and semiclassical Boltzmann theory. The density of states and band structure are studied in detail. The transport coefficients are then calculated with the assumption of the constant relaxation time approximation. We investigated the thermoelectric properties at full range of Sb compositions from x = 0 to x = 1. By using the calculated thermoelectric properties and an averaged thermal conductivity, the figure of merit ZT is obtained. The theoretical investigations show a good agreement with the present experimental data.
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| 7. |
- Lu, P. F., et al.
(författare)
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Investigation on structural, electronic and magnetic propeties of Mn doped Ga12N12 clusters
- 2013
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 48:24, s. 8552-8558
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Tidskriftsartikel (refereegranskat)abstract
- The structural, electronic, and magnetic properties of Ga12N12 cluster doped with monodoped and bidoped Mn atoms have been investigated based on the density functional theory. Substitutional, exohedral, and endohedral configurations are considered. The substitutional doping is found to be most favorable for monodoped clusters, while the bidoped clusters prefer the exohedral isomers. For all the isomer, the magnetic moment is mainly derived from 3d orbitals of Mn atom. The exohedral and endohedral bidoped Ga12N12 clusters all favor antiferromagnetic state.
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| 8. |
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| 9. |
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| 10. |
- Tang, Yunyu, et al.
(författare)
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Solar cells sensitized by porphyrin dyes containing a substituted carbazole donor with synergistically extended absorption and suppressed the dye aggregation
- 2020
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Ingår i: Chinese Chemical Letters. - : Elsevier BV. - 1001-8417 .- 1878-5964. ; 31:7, s. 1927-1930
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Tidskriftsartikel (refereegranskat)abstract
- To achieve high power conversion efficiencies (PCEs), three porphyrin sensitizers have been synthesized and explored to simultaneously enhance the photocurrent (Jsc) and photovoltage (Voc). On basis of the XW4, a benzothiadiazole (BTD) unit has been introduced to afford XW57 with the aim to extend the absorption wavelength and enhance the light harvesting ability. As a result, a Jsc of 13.72 mA/cm2 has been obtained for XW57, higher than that of XW4. On this basis, XW58 has been prepared by modifying the carbazole-based donor with two bulky dihexyloxyphenyl groups, and the superior anti-aggregation character raises the Voc from 781 mV (XW4) to 844 mV. When both the BTD unit and the bulky groups are introduced to the acceptor and donor units, respectively, the resulting sensitizer XW59 exhibits a highest PCE value of 7.34% with synergistically enhanced Jsc of 13.19 mA/cm2 and Voc of 793 mV. These results provide further insight into developing high performance dye-sensitized solar cells
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