2017 |
Mendizabal, F; Mera-Adasme, R; Xu, W H; Sundholm, D Electronic and Optical Properties of Metalloporphyrins of Zinc on Tio2 Cluster in Dye-Sensitized Solar-Cells (Dssc). A Quantum Chemistry Study Artículo de revista Rsc Advances, 7 (68), pp. 42677-42684, 2017. Resumen | Enlaces | BibTeX | Etiquetas: approximation, efficient, energy-levels, excited-states, performance, porphyrin pseudopotentials, sensitizers, surface, thermochemistry @article{mendizabal2017electronic, title = {Electronic and Optical Properties of Metalloporphyrins of Zinc on Tio2 Cluster in Dye-Sensitized Solar-Cells (Dssc). A Quantum Chemistry Study}, author = { F. Mendizabal and R. Mera-Adasme and W.H. Xu and D. Sundholm}, url = {/brokenurl#<Go to ISI>://WOS:000409548200006}, doi = {10.1039/c7ra08648b}, year = {2017}, date = {2017-01-01}, journal = {Rsc Advances}, volume = {7}, number = {68}, pages = {42677-42684}, abstract = {Dye-sensitized solar-cell (DSSC) systems have been investigated by calculating light-absorption and electron-injection processes of the LD13 ([5,15-bis(2,6-(1,1-dimethylethyl)-phenyl)-10-4-dimethylaminophenylethynyl-20-4-carboxy phenylethynyl porphyrinato]zinc-(II)) and YD2-o-C8 ([5,15bis( 2,6-dioctoxyphenyl)-10-(bis(4-hexylphenyl)amino-20-4-carboxyphenylethynyl)porphyrinato]zinc-(II)) dyes adsorbed on a TiO2 cluster simulating the semiconductor. The binding energy of the dyes with the TiO2 clusters has been calculated at the density functional theory (DFT) level using the B3LYP and CAM-B3LYP functionals. The electronic excitation energies have been calculated at the time-dependent DFT (TDDFT) level for the dyes in the gas and solvent phase employing the B3LYP, CAM-B3LYP and BHLYP functionals. The calculated excitation energies have been compared to values obtained at the algebraic diagrammatic construction through second order (ADC(2)) level of theory. The TDDFT calculations with the B3LYP in tetrahydrofuran solvent with the dye and dye-TiO2 models yield excitation energies that agree well with the transitions in the experimental absorption spectra. Changes in the free energy for electron injection support the better performance of the dyes on the TiO2 clusters.}, keywords = {approximation, efficient, energy-levels, excited-states, performance, porphyrin pseudopotentials, sensitizers, surface, thermochemistry}, pubstate = {published}, tppubtype = {article} } Dye-sensitized solar-cell (DSSC) systems have been investigated by calculating light-absorption and electron-injection processes of the LD13 ([5,15-bis(2,6-(1,1-dimethylethyl)-phenyl)-10-4-dimethylaminophenylethynyl-20-4-carboxy phenylethynyl porphyrinato]zinc-(II)) and YD2-o-C8 ([5,15bis( 2,6-dioctoxyphenyl)-10-(bis(4-hexylphenyl)amino-20-4-carboxyphenylethynyl)porphyrinato]zinc-(II)) dyes adsorbed on a TiO2 cluster simulating the semiconductor. The binding energy of the dyes with the TiO2 clusters has been calculated at the density functional theory (DFT) level using the B3LYP and CAM-B3LYP functionals. The electronic excitation energies have been calculated at the time-dependent DFT (TDDFT) level for the dyes in the gas and solvent phase employing the B3LYP, CAM-B3LYP and BHLYP functionals. The calculated excitation energies have been compared to values obtained at the algebraic diagrammatic construction through second order (ADC(2)) level of theory. The TDDFT calculations with the B3LYP in tetrahydrofuran solvent with the dye and dye-TiO2 models yield excitation energies that agree well with the transitions in the experimental absorption spectra. Changes in the free energy for electron injection support the better performance of the dyes on the TiO2 clusters. |
2016 |
Mera-Adasme, R; Xu, W H; Sundholm, D; Mendizabal, F Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells Artículo de revista Physical Chemistry Chemical Physics, 18 (40), pp. 27877-27884, 2016, ISSN: 1463-9076. Resumen | Enlaces | BibTeX | Etiquetas: adsorption, approximation, basis-sets, correlation-energy, dft, efficiency hartree-fock, model, organic-dyes, performance, screening @article{RN305, title = {Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells}, author = { R. Mera-Adasme and W.H. Xu and D. Sundholm and F. Mendizabal}, url = {/brokenurl#<Go to ISI>://WOS:000385180600020}, doi = {10.1039/c6cp04627d}, issn = {1463-9076}, year = {2016}, date = {2016-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {18}, number = {40}, pages = {27877-27884}, abstract = {Solar power is a strong alternative to the currently used fossil fuels in order to satisfy the world's energy needs. Among them, dye-sensitized solar cells (DSSC) represent a low-cost option. Efficient and cheap dyes are currently needed to make DSSCs competitive. Computational chemistry can be used to guide the design of new light-absorbing chromophores. Here, we have computationally studied the lowest excited states of ZnPBAT, which is a recently synthesized porphyrinoid chromophore with high light-absorption efficiency. The calculations have been performed at ab initio correlated levels of theory employing second-order coupled clusters (CC2) and algebraic diagrammatic construction using second order (ADC(2)) methods and by performing density functional theory (DFT) calculations using the time-dependent DFT (TDDFT) approach for excitation energies. The ultraviolet-visible (UV-vis) spectrum calculated at the ADC(2) and CC2 levels agrees well with the experimental one. The calculations show that ZnPBAT has six electronic transitions in the visible range of the absorption spectrum. The ab initio correlated calculations and previously reported experimental data have been used to assess the performance of several well-known density functionals that have been employed in the present TDDFT study. Solvent effects have been estimated by using the conductor-like screening model (COSMO). The influence of the addition of a TiO2 cluster to the chromophore systems has also been investigated. The results indicate that both CAM-B3LYP and Becke's "half-and-half'' (BHLYP) density functionals are appropriate for the studies of excitation energies in the blue range of the visible spectrum for these kinds of porphyrinoid chromophores, whereas the excitation energies of the Q band calculated at the ab initio correlated level are more accurate than those obtained in the present TDDFT calculations. The inclusion of solvent effects has a modest influence on the spectrum of the protonated form of the studied chromophores, whereas solvent models are crucial when studying the absorption spectrum of the anionic chromophore. The calculated UV-vis spectrum for the chromophore anion is not significantly affected by attaching a TiO2 cluster to it.}, keywords = {adsorption, approximation, basis-sets, correlation-energy, dft, efficiency hartree-fock, model, organic-dyes, performance, screening}, pubstate = {published}, tppubtype = {article} } Solar power is a strong alternative to the currently used fossil fuels in order to satisfy the world's energy needs. Among them, dye-sensitized solar cells (DSSC) represent a low-cost option. Efficient and cheap dyes are currently needed to make DSSCs competitive. Computational chemistry can be used to guide the design of new light-absorbing chromophores. Here, we have computationally studied the lowest excited states of ZnPBAT, which is a recently synthesized porphyrinoid chromophore with high light-absorption efficiency. The calculations have been performed at ab initio correlated levels of theory employing second-order coupled clusters (CC2) and algebraic diagrammatic construction using second order (ADC(2)) methods and by performing density functional theory (DFT) calculations using the time-dependent DFT (TDDFT) approach for excitation energies. The ultraviolet-visible (UV-vis) spectrum calculated at the ADC(2) and CC2 levels agrees well with the experimental one. The calculations show that ZnPBAT has six electronic transitions in the visible range of the absorption spectrum. The ab initio correlated calculations and previously reported experimental data have been used to assess the performance of several well-known density functionals that have been employed in the present TDDFT study. Solvent effects have been estimated by using the conductor-like screening model (COSMO). The influence of the addition of a TiO2 cluster to the chromophore systems has also been investigated. The results indicate that both CAM-B3LYP and Becke's "half-and-half'' (BHLYP) density functionals are appropriate for the studies of excitation energies in the blue range of the visible spectrum for these kinds of porphyrinoid chromophores, whereas the excitation energies of the Q band calculated at the ab initio correlated level are more accurate than those obtained in the present TDDFT calculations. The inclusion of solvent effects has a modest influence on the spectrum of the protonated form of the studied chromophores, whereas solvent models are crucial when studying the absorption spectrum of the anionic chromophore. The calculated UV-vis spectrum for the chromophore anion is not significantly affected by attaching a TiO2 cluster to it. |
Diaz, L; Devis, S; Sotomayor, C; González, G; Benavente, E Synthesis and Photocatalytic Activity of Hybrid Layered Zno(Myristic Acid)/Ag Nanoparticles Artículo de revista Materials Letters, 181 , pp. 8-11, 2016, ISSN: 0167-577x. Resumen | Enlaces | BibTeX | Etiquetas: equilibration, fermi-level irradiation, nanocomposites, nanoflakes, nanorods, nanowires, performance, photocatalysis, semiconductors, size uv, visible-light, zno @article{RN298, title = {Synthesis and Photocatalytic Activity of Hybrid Layered Zno(Myristic Acid)/Ag Nanoparticles}, author = { L. Diaz and S. Devis and C. Sotomayor and G. Gonz\'{a}lez and E. Benavente}, url = {/brokenurl#<Go to ISI>://WOS:000381540100003}, doi = {10.1016/j.matlet.2016.05.126}, issn = {0167-577x}, year = {2016}, date = {2016-01-01}, journal = {Materials Letters}, volume = {181}, pages = {8-11}, publisher = {2016 Elsevier B.V.}, abstract = {A new hybrid hetero nanocomposite, consisting of ZnO(myristic acid)/Ag-NPs, has been synthesized. The nanocomposite, made up of single ZnO nanosheets sandwiched between myristic acid self-assembled monolayers was synthesized and decorated with metal nanoparticles by chemical solution and tested in the photodegradation of methylene blue under UV light irradiation. The product displayed significant photocatalytic activity for degradation of the dye, and the activity was improved by a factor of three compared to bulk ZnO under similar conditions. The observed photodegradation efficiency is discussed in terms of the confinement of the semiconductor in the two dimensional structure, the adsorption ability of the organic component and the plasmonic absorption of Ag nanoparticles, which makes them act as electron wells, thus promoting charge separation and a reduced recombination rate.}, keywords = {equilibration, fermi-level irradiation, nanocomposites, nanoflakes, nanorods, nanowires, performance, photocatalysis, semiconductors, size uv, visible-light, zno}, pubstate = {published}, tppubtype = {article} } A new hybrid hetero nanocomposite, consisting of ZnO(myristic acid)/Ag-NPs, has been synthesized. The nanocomposite, made up of single ZnO nanosheets sandwiched between myristic acid self-assembled monolayers was synthesized and decorated with metal nanoparticles by chemical solution and tested in the photodegradation of methylene blue under UV light irradiation. The product displayed significant photocatalytic activity for degradation of the dye, and the activity was improved by a factor of three compared to bulk ZnO under similar conditions. The observed photodegradation efficiency is discussed in terms of the confinement of the semiconductor in the two dimensional structure, the adsorption ability of the organic component and the plasmonic absorption of Ag nanoparticles, which makes them act as electron wells, thus promoting charge separation and a reduced recombination rate. |
2015 |
Mendizabal, F; Lopez, A; Arratia-Perez, R; Zapata-Torres, G Interaction of Ld14 and Tio2 in Dye-Sensitized Solar-Cells (Dssc): A Density Functional Theory Study Artículo de revista Computational and Theoretical Chemistry, 1070 , pp. 117-125, 2015, ISSN: 2210-271x. Resumen | Enlaces | BibTeX | Etiquetas: coordination electronic-structure, energies, energy-levels, ld14-tio2 model, molecules, organic-dyes, performance, porphyrin properties, pseudopotentials sensitizers, spectroscopic spectrum, surface, tddft @article{RN252, title = {Interaction of Ld14 and Tio2 in Dye-Sensitized Solar-Cells (Dssc): A Density Functional Theory Study}, author = { F. Mendizabal and A. Lopez and R. Arratia-Perez and G. Zapata-Torres}, url = {/brokenurl#<Go to ISI>://WOS:000361576000017}, doi = {10.1016/j.comptc.2015.08.005}, issn = {2210-271x}, year = {2015}, date = {2015-01-01}, journal = {Computational and Theoretical Chemistry}, volume = {1070}, pages = {117-125}, publisher = {2015 Elsevier B.V.}, abstract = {The interaction and electron injection processes of the LD14 dye on TiO2 cluster (anatase phase) in dyesensitized solar cells (DSSCs) have been studied through calculations based on density functional theory (DFT) at the B3LYP, PBE and TPSS levels along with dispersion effects. The interaction of the LD14 dye with the TiO2 clusters was quantified using the DFT-D3 levels. The TDDFT calculations with the B3LYP-D3 in phase solvent (THF) in the LD14 and LD14-TiO2 models are the most suitable for describing the observed absorption energy bands. The free energy changes for electron injection support the better performance of LD14 on the TiO2 clusters.}, keywords = {coordination electronic-structure, energies, energy-levels, ld14-tio2 model, molecules, organic-dyes, performance, porphyrin properties, pseudopotentials sensitizers, spectroscopic spectrum, surface, tddft}, pubstate = {published}, tppubtype = {article} } The interaction and electron injection processes of the LD14 dye on TiO2 cluster (anatase phase) in dyesensitized solar cells (DSSCs) have been studied through calculations based on density functional theory (DFT) at the B3LYP, PBE and TPSS levels along with dispersion effects. The interaction of the LD14 dye with the TiO2 clusters was quantified using the DFT-D3 levels. The TDDFT calculations with the B3LYP-D3 in phase solvent (THF) in the LD14 and LD14-TiO2 models are the most suitable for describing the observed absorption energy bands. The free energy changes for electron injection support the better performance of LD14 on the TiO2 clusters. |
2017 |
Electronic and Optical Properties of Metalloporphyrins of Zinc on Tio2 Cluster in Dye-Sensitized Solar-Cells (Dssc). A Quantum Chemistry Study Artículo de revista Rsc Advances, 7 (68), pp. 42677-42684, 2017. |
2016 |
Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells Artículo de revista Physical Chemistry Chemical Physics, 18 (40), pp. 27877-27884, 2016, ISSN: 1463-9076. |
Synthesis and Photocatalytic Activity of Hybrid Layered Zno(Myristic Acid)/Ag Nanoparticles Artículo de revista Materials Letters, 181 , pp. 8-11, 2016, ISSN: 0167-577x. |
2015 |
Interaction of Ld14 and Tio2 in Dye-Sensitized Solar-Cells (Dssc): A Density Functional Theory Study Artículo de revista Computational and Theoretical Chemistry, 1070 , pp. 117-125, 2015, ISSN: 2210-271x. |