Generalized Response Theory for a Photoexcited Many-Atom System

Micha, David A.

doi:10.1016/bs.aiq.2015.03.004

Cited by 11 publications

(19 citation statements)

References 30 publications

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“…In particular, we employed the HES06 hybrid functional of Heyd, Scuseria, and Ernzerhof, 26,27 a well-established treatment for the band gap analysis of semiconductors including TiO 2 . 28 This combined RDM-DFT treatment 29,30 has provided UV−vis absorption spectra in very good agreement with the experiment for the Cu 5 -decorated rutile TiO 2 (110) surface. 19 If not explicitly mentioned otherwise, distances and energies are given in angstrom (1 = 10 10 m) and electronvolt (1 eV = 1.602176565(35) 10 −19 m 2 kg s 2 ) units, respectively.…”

Section: Methodsmentioning

confidence: 55%

Exploring the Catalytic Properties of Unsupported and TiO₂-Supported Cu₅ Clusters: CO₂ Decomposition to CO and CO₂ Photoactivation

2019

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In this work, we explore the decomposition of CO2 on unsupported and TiO2-supported Cu5 clusters via computational modeling, using both finite cluster and periodic slab structures of the rutile TiO2(110) surface. While the energy needed for C=O bond breaking is already significantly reduced upon adsorption onto the unsupported metal catalyst (it drops from 7.8 to 1.3 eV), gas desorption before bond activation is still the inevitable outcome due to the remaining barrier height even at 0 K. However, when the Cu5 cluster itself is supported on TiO2, reactant and product adsorption is strongly enhanced, the barrier for bond breaking is further reduced, and a spontaneous decomposition of the molecule is predicted. This finding is linked to our previous work on charge-transfer processes in the Cu5–TiO2 system triggered by solar photons, since a combination of both phenomena at suitable temperatures would allow for a photoinduced activation of CO2 by sunlight.

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Section: Methodsmentioning

confidence: 55%

Exploring the Catalytic Properties of Unsupported and TiO₂-Supported Cu₅ Clusters: CO₂ Decomposition to CO and CO₂ Photoactivation

2019

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“…15 The relaxation processes involved are described by the reduced density matrix (RDM) approach in the Redeld approximation, 46 based on orbitals taken from calculations employing the HSE06 hybrid functional. This combined RDM-DFT treatment developed by Micha and Kilin 47,48 is already a well-established tool in describing the optical spectra of subnano metal clusters adsorbed on semiconductor surfaces 80 (see, e.g., ref. 20 and 50-52).…”

Section: Periodic Calculationsmentioning

confidence: 99%

“…15 In order to calculate the UV-Vis absorption spectra, we employed reduced density matrix (RDM) theory within the Redeld approximation, 46 combined with DFT calculations using the HSE06 functional. This combination of RDM and DFT, proposed by Micha and collaborators, [47][48][49] has been successfully applied to silver 20,50-52 and copper 15,19 clusters on semiconductor TiO 2 and silicon surfaces. 15,19,20,[50][51][52][53] The results from our computational calculations and spectroscopy (diffuse reectance and X-ray absorption) measurements are presented and discussed in Section 2.…”

Section: Introductionmentioning

confidence: 99%

Exploring the properties of Ag₅–TiO₂ interfaces: stable surface polaron formation, UV-Vis optical response, and CO₂ photoactivation

et al. 2020

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Using a combination of first-principles modelling, X-ray absorption spectroscopy, and diffuse reflectance spectroscopy measurements, we explore the properties of Ag 5 -modified TiO 2 surfaces. A general electron polarization phenomenon associated with surface polarons on TiO 2 has been revealed theoretically and confirmed experimentally. First, the Ag 5 cluster donates an electron to TiO 2 , leading to the formation of polaronic Ti 3+ 3d 1 states on the rutile TiO 2 (110) surface. The analysis of polarization effects in the nearby electronic structure accompanying the polaron formation is confirmed with X-ray absorption spectroscopy measurements at the Ti K-edge of TiO 2 nanoparticles. Next, the UV-Vis optical absorption spectrum of the polaronic state is also computationally modelled and an enlargement of the polaron wavefunction is predicted. Moreover, we find an overall improvement of the UV-Vis optical response of the material through diffuse reflectance spectroscopy measurements. Finally, we predict that charge-transfer processes at the Ag 5 -TiO 2 interface triggered by solar photons might allow for a photoinduced activation of CO 2 by sunlight. † Electronic supplementary information (ESI) available: Complementary results from the rst-principles modelling: polaronic states in reduced TiO 2 (110) surfaces, and characterization of the most relevant orbitals in the photoexcitation of the Ag 5 /TiO 2 (110) system. See

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“…In order to calculate light absorption in the system, we model the involved relaxation processes by means of the reduced density matrix (RDM) approach in the Redfield approximation 27 and using an electronic basis set of orbitals generated from DFT calculations. 48,49 When a monochromatic electromagnetic field of frequency O is applied, the evolution equation for the RDM, r, in the Schrödinger picture reads,…”

Section: Theoretical Approaches Using Periodic Modelsmentioning

confidence: 99%

Ab initio design of light absorption through silver atomic cluster decoration of TiO₂

Lara‐Castells

Cabrillo

Micha

et al. 2018

Phys. Chem. Chem. Phys.

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A first-principles study of the stability and optical response of subnanometer silver clusters Agn (n ≤ 5) on a TiO2(110) surface is presented. First, the adequacy of the vdW-corrected DFT-D3 approach is assessed using the domain-based pair natural orbital correlation DLPNO-CCSD(T) calculations along with the Symmetry-Adapted Perturbation Theory [SAPT(DFT)] applied to a cluster model. Next, using the DFT-D3 treatment with a periodic slab model, we analyze the interaction energies of the atomic silver clusters with the TiO2(110) surface. Finally, the hybrid HSE06 functional and a reduced density matrix treatment are applied to obtain the projected electronic density of states and photo-absorption spectra of the TiO2(110) surface, with and without adsorbed silver clusters. Our results show the stability of the supported clusters, the enhanced light absorbance intensity of the material upon their deposition, and the appearance of intense secondary broad peaks in the near-infrared and the visible regions of the spectrum, with positions depending on the size and shape of the supported clusters. The secondary peaks arise from the photo-induced transfer of electrons from intra-band valence 5s orbitals of the noble-metal cluster to 3d Ti band states of the supporting material.

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Generalized Response Theory for a Photoexcited Many-Atom System

Cited by 11 publications

References 30 publications

Exploring the Catalytic Properties of Unsupported and TiO₂-Supported Cu₅ Clusters: CO₂ Decomposition to CO and CO₂ Photoactivation

Exploring the Catalytic Properties of Unsupported and TiO₂-Supported Cu₅ Clusters: CO₂ Decomposition to CO and CO₂ Photoactivation

Exploring the properties of Ag₅–TiO₂ interfaces: stable surface polaron formation, UV-Vis optical response, and CO₂ photoactivation

Ab initio design of light absorption through silver atomic cluster decoration of TiO₂

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Generalized Response Theory for a Photoexcited Many-Atom System

Cited by 11 publications

References 30 publications

Exploring the Catalytic Properties of Unsupported and TiO2-Supported Cu5 Clusters: CO2 Decomposition to CO and CO2 Photoactivation

Exploring the Catalytic Properties of Unsupported and TiO2-Supported Cu5 Clusters: CO2 Decomposition to CO and CO2 Photoactivation

Exploring the properties of Ag5–TiO2 interfaces: stable surface polaron formation, UV-Vis optical response, and CO2 photoactivation

Ab initio design of light absorption through silver atomic cluster decoration of TiO2

Contact Info

Product

Resources

About

Exploring the Catalytic Properties of Unsupported and TiO₂-Supported Cu₅ Clusters: CO₂ Decomposition to CO and CO₂ Photoactivation

Exploring the Catalytic Properties of Unsupported and TiO₂-Supported Cu₅ Clusters: CO₂ Decomposition to CO and CO₂ Photoactivation

Exploring the properties of Ag₅–TiO₂ interfaces: stable surface polaron formation, UV-Vis optical response, and CO₂ photoactivation

Ab initio design of light absorption through silver atomic cluster decoration of TiO₂