27 SEPTEMBER 2022: It is our preasure to announce that María Pilar de Lara-Castells was elected Chair of the COST ACTION CA21101 - CONFINED MOLECULAR SYSTEMS: FROM A NEW GENERATION OF MATERIALS TO THE STARS (COSY), approved in May 2022, at the kick-off meeting celebrated the 27th of September at Brussels. See: http://www.cost.eu/CA21101

This COST Action aims to provide a computationally and experimentally sound foundation for the fundamental understanding and control of confined molecular systems. It will involve the development of joined research and ideas through more than 130 participating groups, from more than 30 countries. The excellence of COSY relies on its international and inter- and multi-disciplinary character, as a project that gathers physical chemists, molecular physicists, theoretical and experimental chemists and physicists, spectroscopists, astrochemists, astrophysicists, astronomers, atmospheric scientists, biochemists and biophysicists, and on inter-sectorial collaborations through universities, research centers, and a sustainable industry.

More information can be found at the COST webpage, including an application to join the WGs.  See: http://www.cost.eu/CA21101
Happy birthday to COSY and congratulations to all proposers of this COST Action!!!

 

14 FEBRUARY 2022: 

 

Happy to share that our Feature Article has been highlighted in the Inside Cover of JCIS. I am greatly thankful to all my Collaborators within the topic of the FA, to the Editorial Team of JCIS, and to the CSIC Open Access Support Initiative (URICI). The Link is at:

https://doi.org/10.1016/S0021-9797(22)00227-2

10 FEBRUARY 2022:

*Postdoctoral Research Scientist in Theoretical Chemistry and Molecular Physics at IFF-CSIC (AbinitSim Unit)*

We are looking for a *postdoctoral research scientist*. The position will be opened in 1 April and the candidate will be hired during the next 3-4 months. The postdoctoral researcher is expected to work in the project "Confined Molecular Systems: The New Generation of Materials", dealing with quantum chemistry, molecular dynamics simulations and machine learning algorithms to investigate, at the most fundamental level, the special properties of (e.g., subnanometric) metal clusters as well as their integration into materials interacting with the environment to further boost their performance in applications such as energy conversion and photocatalysis. Atomistic simulations on helium droplet-mediated surface deposition processes are also included.

The candidate should have a strong background in quantum chemistry, molecular physics and python programming. Relevant areas of expertise might include application of machine learning methods to materials or molecular dynamics to intermolecular interactions.

Interested candidates should contact M.P. de Lara-Castells sending a CV including research interests and 2-3 reference letters.

1 FEBRUARY 2022: Jaime Garrido Aldea, student from the University of Cantabria joined the AbinitSim Unit, you are very welcome Jaime!.

16-17 DECEMBER 2021: We had with us to Berta Fernández, our teammate within the COSYES project. You are very welcome Berta!.

1 SEPTEMBER 2021: Our National Project "Confined Molecular Systems: The New Generation of Materials" (COSYES) got funded. This marks the start of a new stage for our AbinitSim Unit. This project will be runned till August 2025. The first COSYES meeting, joining our international team, is planned on 7-8 April 2022, at CSIC Central Campus, Madrid.

6 NOVEMBER 2020: We have created a video summarizing our research on supported subnanometer-sized clusters. Click here to listen and visualize it.

22 OCTOBER 2020: Our paper in the memory of Professor Carmela Valdemoro has just been published:

https://aip.scitation.org/doi/10.1063/5.0029099

4 OCTOBER 2020: Our contribution entitled

A new generation of subnanometer-sized materials reveals a general surface polarons property

by María Pilar de Lara-Castells and Salvador Miret-Artés

was accepted as a 'Feature' in Europhysics News. Click here to see the preprint.

25 SEPTEMBER 2020:  Today our group got the first research podcast about the properties of TiO₂-supported subnanometer-sized metal clusters.  

1 SEPTEMBER 2020:  Today Ricardo Garsed,  under-graduate student (in Chemistry) from the Universidad Autónoma de Madrid joined our group. Your are very welcome Ricardo!.

Here comes a photograph of my two outstanding students Patricia López-Caballero (right) and Ricardo Garsed (left).

8 JUNE 2020

A joint paper together with Alexander O. Mitrushchenkov (Univ. Gustave Eiffel) is published in the Journal of Physical Chemistry Letters: Highly accurate full quantum computations allows predicting the formation of one-dimensional crystal of deuterium inside carbon nanotubes. It suggests an step forward in improved fundamental understanding of hydrogen solid formation for optimized energy storage. If you are interested, please have a look to our paper, it is open-access:

From Molecular Aggregation to a One-Dimensional Quantum Crystal of Deuterium Inside a Carbon Nanotube of 1 nm Diameter

María Pilar de Lara-Castells and Alexander O. Mitrushchenkov

 

8 MARCH 2020

A SUBNANOMETER SILVER CLUSTER HAS REVEALED A GENERAL ELECTRON POLARIZATION PHENOMENA OF SURFACE POLARONS

(A ``paper story" written by María Pilar de Lara-Castells)

The polaron concept was first proposed by Landau in 1933 [1] to characterize an electron moving in a dielectric crystal such as titanium dioxide, where the O^2- ions depart from the Ti atom hosting the polaron to screen its self-trapped Ti³⁺ 3d¹ electron.  This lattice distortion is known as the phonon cloud. The entity formed by the electron and its associated phonon cloud is the polaron. The effective mass of the polaron is larger than that of the free electron and, accordingly, it is also ``slower". From a very simplified picture, a surface polaron could be thought as a travelling "slow" electron onto the given surface since it "cannot escape its shadow".

In our latest work [2], we have found that there is also an electron polarization phenomena accompanying the polaron formation: The self-trapped Ti³⁺ 3d¹ electron repels nearby oxygen ions and attracts nearby titanium cations, which, in turn, affects their electronic structure, causing the transfer of electronic charge from Ti⁴⁺ cations to O^2- ions. The stabilization of the surface polaron was possible through decoration of the TiO₂ nanoparticles with subnanometer silver clusters (Ag₅). In this way, we found three different evidences of the electron polarization phenomena: (1) via a direct first-principles analysis of Ti(3d) orbitals population; (2)  through X-ray spectroscopic measurements; (3) via first-principles simulations of the UV-Vis spectra of the composite Ag₅/TiO₂ system.

I am very happy of having led the work, and greatly thankful to all my co-authors: to my outstanding student, Patricia López-Caballero (AbinitSim Unit, Institute of Fundalmental Physics at CSIC), to Salvador Miret-Artés (Institute of Fundamental Physics at CSIC), to M. Arturo Lopez Quintela (co-funder of Nanogap) and David Buceta from the University of Santiago de Compostela (USC), and to José Martín Ramallo-López, Lisandro J. Giovanetti, and Félix Requejo from CONICET at Argentina. Also, I would like to remark that the development of the work was possible using the facilies of the CESGA SuperComputer Center (Galicia, Spain), where the first-principles simulations were performed, and of the Brazilian Synchroton Light Laboratory (LNSN), where the X-ray measurements were taken. Our work has been also possible thanks to the group of M. Arturo López-Quintela (USC) because they have developed the special technique rendering the synthesis of subnanometer metal clusters feasible.

If you want to know more, please read the paper, it is open-access:

https://doi.org/10.1039/D0TA00062K

[1] L. D. Landau and S. I. Pekar, Effective mass of a polaron, Zh. Eksp. Teor. Fiz. 18, 419–423 (1948) [in Russian], English translation: Ukr. J. Phys., Special Issue, 53, pp. 71–74 (2008).

[2] P. López-Caballero, J. M. Ramallo-López, L. J. Giovanetti, D. Buceta, S. Mirét-Artés, M. Arturo López-Quintela, F. Requejo, M. P. de Lara-Castells,*  Exploring the properties of Ag₅-TiO₂ interfaces: stable surface polarons formation, UV-Vis optical response, and CO₂ photoactivation, J. Mat. Chem. A. (2020)  https://doi.org/10.1039/D0TA00062K

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10 SEPTEMBER 2019: Patricia López-Caballero has co-authored her first paper. Congratulations Patricia!!. Press here to see the paper.

10 JULY 2019: A new report about our recent reserach has been published at https://www.lnls.cnpem.br/enhancing-solar-energy-production/

3 MAY 2019: A new report about our recent research has been published at CESGA. Press here to see the report.

8 APRIL 2019: The Book Of Abstracts from the MOLIM WG3 meeting "Ab-Initio Modelling of Molecular Processes Under Confinement" is already available. Press here.

1 APRIL 2019: Today, Patricia López-Caballero, graduate student (in Chemistry) from the Universidad Autónoma de Madrid, has been incorporated into the AbinitSim group. Welcome Patricia!.

26 MARCH 2019: Within the framework of our collaboration with the Graz University of Technology (Austria), the University of Santiago de Compostela (Spain), and CONICET (Argentina), we have just published an article on the deposition of subnanometer-sized Cu₅ clusters onto TiO₂ surfaces. The work is entitled "Increasing the optical response of TiO₂ and extending it into the visible through surface activation with highly stable Cu₅ clusters" (de Lara-Castells, Hauser, Ramallo-López, Buceta, Giovanetti, López-Quintela, Requejo; Journal of Materials Chemistry A 7 (2019) 7489).

MOTIVATION

TiO₂ is one of the most popular materials for applications such as solar energy conversion and photocatalysis. However, its large band-gap (3-3.2 eV) makes that ultraviolet irradiation is necessary to trigger photo-catalytic reactions. The UV part is less than 8% of the solar radiation so that the reaction rate divided by the photon flux is less than 10%. In our work, we demonstrate via ab-initio modelling that the optical properties of TiO₂ are much improved upon deposition of the Cu₅ clusters and our findings are further supported by selected experiments. The copper cluster donates electronic charge to TiO₂, loosing its magnetic moment and leading to the formation of a small polaron state, which explains X-ray absorption spectroscopy data. More importantly, a monolayer of highly stable copper clusters is formed, which is not only enhancing the overall absorption, but also extending it into the visible region via a direct photo-induced electron transfer and formation of a charge-separated state. The synthesis of these subnanometer-sized metal clusters was achieved using a novel technique that has opened the door to applications such a cancer-therapeutic drugs (www.nanogap.es).

Overall, our study illustrates the suitability of ab-initio modelling in predicting useful properties of subnanometer-sized metal clusters under confinement in the surface of technologically relevant materials. We are currently extending our work to specific photo-induced reactions. So Stay Tuned!.

 

SPANISH VERSION:

26 de Marzo de 2019: Hemos publicado un trabajo que muestra cómo pueden mejorarse las propiedades ópticas de superficies de TiO₂ mediante el depósito de agregados subnanométricos de cobre (Cu₅). El TiO₂ es una de los materiales más populares en aplicaciones fotocatalíticas y de conversión de la energía solar debido a su abundancia, no toxicidad, y estabilidad química. Sin embargo, su gran ancho de banda  (entre 3 y 3.2 eV) hace necesaria la absorción de radiación ultravioleta para desancadenar reacciones fotoinducidas. Esta característica no deseada limita severamente las aplicaciones del TiO₂ ya que la parte UV comprende solo el 5-8% de la energía solar. Como consecuencia, la tasa de formación de productos de reacción por fotón incidente es típicamente inferior al 10% en fotocatalizadores basados en TiO₂. En nuesto trabajo, hemos demostrado cómo el depósito de agregados de Cu₅ de tamaño subnanométrico mejora en órdenes de magnitud la absorción de fotones del material en el ultravioleta, logrando que la absorción se extienda a la región visible. Además, se muestra cómo los agregados Cu₅ inducen la formación de pequeños polarones en la superficie de TiO₂. El trabajo ilustra la capacidad predictiva de modelizaciones ab-initio multiescala de nuevos materiales nanoestructurados, habiendo sido los resultados teóricos corroborados mediante medidas experimentales.

El artículo es open access y puede ser descargado desde:

https://pubs.rsc.org/en/Content/ArticleLanding/2019/TA/C9TA00994A#!divAbstract