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2. |
- Chen, Ruikui, et al.
(författare)
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Photoinduced intramolecular charge-transfer state in thiophene-π-conjugated donor-acceptor molecules.
- 2008
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Ingår i: Journal of Molecular Structure. - : Elsevier BV. - 0022-2860 .- 1872-8014. ; 876:1-3, s. 102-109
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Tidskriftsartikel (refereegranskat)abstract
- Novel thiophene-π-conjugated donor-acceptor mols., 5-[2-(1,2,2,4-tetramethyl-1,2,3,4-tetrahydroquinolin-6-yl)-vinyl]-thiophene-2-carbaldehyde (QTC) and (1-cyano-2-{5-[2-(1,2,2,4-tetramethyl-1,2,3,4-tetrahydroquinolin-6-yl)-vinyl]-thiophen-2-yl}-vinyl)-phosphonic acid di-Et ester (QTCP), were designed and synthesized. Combined exptl. and theor. methods were performed to investigate the photoinduced intramol. charge-transfer (ICT) processes of these compds. Steady-state absorption and fluorescence measurements in different solvents indicate the photoinduced ICT characters of QTC and QTCP. Solvent dependency of the large Stokes shifts and high dipole moment of the excited state also support the charge-transfer character of the excited state. Theor. calcns. based on time-dependent d. functional theory (TDDFT) method were performed to investigate ICT states of these compds. The results reveal that the excited states have adopted a distortion of the C=C double bond between the donor moiety and the thiophene-π-bridge. [on SciFinder(R)]
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3. |
- Dong, Weibing, et al.
(författare)
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Preparation, structures and electrochemical property of phosphine substituted diiron azadithiolates relevant to the active site of Fe-only hydrogenases
- 2007
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Ingår i: Journal of Inorganic Biochemistry. - : Elsevier BV. - 0162-0134 .- 1873-3344. ; 101:3, s. 506-513
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Tidskriftsartikel (refereegranskat)abstract
- Mono- and di-phosphine diiron azadithiolate complexes [{(mu-SCH2)(2)N(4-NO2C6H4)}Fe-2(CO)(5)(PMe3)] (2), [{(mu-SCH2)(2)N(4NO(2)C(6)H(4))} {Fe(CO)(2)L}(2)] (3, L = PMe3; 4, PMe2Ph) and the mu-hydride diiron complex [3(FeHFe)](+)[PF6](-) were prepared as biontimetic models of the active site of Fe-only hydrogenases. The complexes 2-4 and [3(FeHFe)](+)[PF6](-) were characterized by IR P-31, H-1 and C-13 NMR spectra and their molecular structures were determined by single crystal X-ray analyses. The PMe3 ligand in complex 2 lies on the basal position. The PMe3-disubstituted complex 3 exists as two configuration isomers, transoid basal/basal and apical/basal, in the crystalline state, while two PMe2Ph ligands of 4 are in an apical/basal orientation. The variable temperature P-31 NMR spectra of 2 and 3 were made to have an insight into the existence of the possible conformation isomers of 2 and 3 in solution. The [3(FeHFe)](+) cation possesses the sole transoid ba/ba geometry as other reported mu-hydride diiron analogues. The electrocatalytic property of {(mu-SCH2)(2)NC6H5}[Fe(CO)(2)PMe3](2) (5) was studied for proton reduction in the presence of HOAc.
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4. |
- Jiang, J., et al.
(författare)
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Highly active and durable electrocatalytic water oxidation by a NiB0.45/NiOx core-shell heterostructured nanoparticulate film
- 2017
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 38, s. 175-184
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Tidskriftsartikel (refereegranskat)abstract
- On the way to energy-efficient and cost-effective hydrogen production by electrochemical or photoelectrochemical water splitting, it is of primary importance to develop highly active and durable water oxidation electrocatalysts based on earth-abundant elements. Here we report a highly active, robust, cheap, and facilely fabricated O2-evolving catalyst on a Cu foil, NiB0.45-250/Cu, which forms a NiB0.45/NiOx core-shell heterostructured nanoparticulate film during anodic electrolysis. The performance of NiB0.45-250/Cu, to produce 10 mA cm−2 at 296 mV overpotential in 1 M KOH over 60 h, is at par with the best efficiency of earth-abundant electrocatalysts reported to date and surpasses that of IrO2-loaded copper electrode under identical conditions. Experimental evidence and theoretical calculations reveal the correlations of B/Ni atomic ratio and annealing temperature with the morphology, surface microtexture, electrochemical active surface area, and electrical conductivity of NiBx films. Optimal combination of these factors can evidently enhance the catalytic activity of nickel boride electrocatalysts.
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5. |
- Liu, Chang, et al.
(författare)
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A dendritic Sb2Se3/In2S3 heterojunction nanorod array photocathode decorated with a MoSx catalyst for efficient solar hydrogen evolution
- 2020
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:44, s. 23385-23394
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Tidskriftsartikel (refereegranskat)abstract
- Developing cost-effective photocathodes that show desirable performance for use in commercial photoelectrochemical water splitting devices remains a fundamental and practical challenge. Sb2Se3 semiconductors satisfy most of the demands expected for an ideal highly efficient photocathode, including favorable cost and optoelectronic properties. Herein, we have demonstrated outstanding photoelectrodes using a noble-metal-free catalyst, namely, a MoSx-decorated low-cost Sb2Se3/In2S3 heterojunction, as the photocathode. This enabled a maximum photocurrent density of up to -27 mA cm(-2) (0 V vs. RHE, 100 mW cm(-2), AM 1.5G filter) with a remarkable half solar-to-hydrogen conversion efficiency (STH) of 2.6%, obtained via decreasing charge recombination and accelerating charge transfer through morphological optimization of the In2S3 layer.
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6. |
- Liu, Jinxuan, et al.
(författare)
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A new class of epitaxial porphyrin metal-organic framework thin films with extremely high photocarrier generation efficiency : promising materials for all-solid-state solar cells
- 2016
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 4:33, s. 12739-12747
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the fabrication of a new class of epitaxial porphyrin metal-organic framework thin films whose photophysical properties can be tuned by the introduction of electron-donating diphenylamine (DPA) groups into the porphyrin skeleton. The attachment of DPA groups results in strongly improved absorption characteristics, yielding the highest photocarrier generation efficiency reported so far. DFT calculations identify a shift of the charge localization pattern in the VBM (lowest unoccupied molecular orbital), confirming that the introduction of the DPA groups is the main reason for the shift of the optical absorption spectrum and the improved photocurrent generation.
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7. |
- Liu, X., et al.
(författare)
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Bromide-Mediated Photoelectrochemical Epoxidation of Alkenes Using Water as an Oxygen Source with Conversion Efficiency and Selectivity up to 100%
- 2022
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 144:43, s. 19770-19777
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Tidskriftsartikel (refereegranskat)abstract
- In a photoelectrochemical (PEC) cell, the production of solar fuels such as hydrogen is often accompanied either by the oxidation of water or by the oxidation of organic substrates. In this study, we report bromide-mediated PEC oxidation of alkenes at a mesoporous BiVO4 photoanode and simultaneous hydrogen evolution at the cathode using water as an oxygen source. NaBr as a redox mediator was demonstrated to play a dual role in the PEC organic synthesis, which facilitates the selective oxidation of alkenes into epoxides and suppresses the photocorrosion of BiVO4 in water. This method enables a near-quantitative yield and 100% selectivity for the conversion of water-soluble alkenes into their epoxides in H2O/CH3CN solution (v/v, 4/1) under simulated sunlight without the use of noble metal-containing catalysts or toxic oxidants. The maximum solar-to-electricity efficiency of 0.58% was obtained at 0.39 V vs Ag/AgCl. The obtained epoxide products such as glycidol are important building blocks of the chemical industry. Our results provide an energy-saving and environment-benign approach for producing value-added chemicals coupled with solar fuel generation.
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8. |
- Liu, X. E., et al.
(författare)
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A novel ruthenium(II) tris(bipyridine)-zinc porphyrin-rhenium carbonyl triad : synthesis and optical properties
- 2006
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 62:15, s. 3674-3680
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Tidskriftsartikel (refereegranskat)abstract
- A novel ruthenium(II) tris(bipyridine)-zinc porphyrin-rhenium carbonyl triads and its free base porphyrin derivative were synthesized and characterized by H-1, C-13 NMR, UV-vis, mass-spectrometry and elemental analysis. The redox potentials of the two Compounds were measured and compared to their corresponding reference complexes. The fluorescence and transient absorption spectra of the two complexes revealed the features of two different pathways for possible photoinduced intramolectular electron transfer or energy transfer in the triads.
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9. |
- Liu, X., et al.
(författare)
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Synthesis, characterization and some properties of amide-linked porphyrin-ruthenium(II) tris(bipyridine) complexes
- 2005
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 61:23, s. 5655-5662
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Tidskriftsartikel (refereegranskat)abstract
- A new molecular dyad, comprised of a zinc-porphyrin and a ruthenium(II) tris(bipyridine) complex linked through an amide bond has been synthesized and characterized by H-1, C-13 NMR, UV-vis, mass-spectrometry and elemental analysis. The electrochemistry as well as the steady-state emission properties were investigated. The redox behavior of the dyad exhibits a favorable reversible characteristic. Substantial quenching of porphyrin emission was found when the Q hand of 5 and 5-Zn was selectively photoexcited. This observation suggests a quenching mechanism with possible intramolecular electron transfer or energy transfer between the Ru(bpy)(3) moiety and the porphyrin free-base or Zn porphyrin moieties.
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10. |
- Liu, Xien, et al.
(författare)
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Synthesis, electrochemical, and photophysical studies of multicomponent systems based on porphyrin and ruthenium(II) polypyridine complexes
- 2007
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 63:37, s. 9195-9205
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Tidskriftsartikel (refereegranskat)abstract
- Two ruthenium tris-bipyridine functionalized porphyrins 4, 8 and their Zn derivatives 4-Zn, 8-Zn were designed, synthesized, and characterized. The redox potentials of these complexes as well as their corresponding monomeric reference porphyrin and ruthenium bipyridine complexes were also measured for comparison. Primary dynamic studies on the electron injection and backing recombination between these complexes and TiO2 nanoparticles were carried out by means of transient absorption spectroscopy. The results indicate that a long-lived charge separation state was obtained in these assemblies.
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