Photoactive Nanostructures: Implications in Photocatalysis

We aim at understanding the interplay of size, shape and morphology of semiconducting nanostructures (e.g. TiO2, WO3 and ZnO) and its consequences on the electronic and excited states properties. Different structural and environmental aspects are investigated like the oxygen vacancies, doping (e.g., carbon, nitrogen) and hydrated systems.

Electronic properties are usually analyzed using the sophisticated GW and TDDFT methods. Topological excited states descriptors have been recently developed in CompuMat to localize and identify the photogenerated species (electrons and holes). This allows us to classify the photactive nanostructures considering the electron-hole distance and overlapping densities. 

The ultimate goal is to investigate the reactivity of these nanosystems in the excited states by investigating the mechanisms of the water splitting reaction and the CO2 photoconversion. 

SOME RELATED PUBLICATIONS

V. Diez-Cabanes, Ángel Morales-García*, F. Illas, M. Pastore. Tuning the Interfacial Energetics in WO3/WO3 and WO3/TiO2 Heterojunctions by Nanostructure Morphological Engineering. J. Phys. Chem. Lett. 2021, 12, 11528-11533 (Link)

L. Mino, Ángel Morales-García*, S. T. Bromley, F. Illas. Understanding the Nature and Location of Hydroxyl Groups on hydrated Titania Nanoparticles. Nanoscale 2021, 13, 6577-6585 (Link)   

Ángel Morales-García*, R. Valero, F. Illas. Morphology of TiO2 Nanoparticles as Figerprint for the Transient Absorption Spectra: Implications for Photocatalysis. J. Phys. Chem. C 2020, 124, 11819-11824 (Link)

R. Valero, Ángel Morales-García, F. Illas. Investigating the Character of Excited States in TiO2 Nanoparticles from Topological Descriptors: Implications for Photocatalysis. Phys. Chem. Chem. Phys. 2020, 22, 3017-3029 (Link)

Ángel Morales-García*, R. Valero, F. Illas. Electronic Properties of Realistic Anatase TiO2 Nanoparticles from G0W0 Calculations on a Gaussina and Plane Waves Based Scheme. J. Chem. Theory Comput. 2019, 15, 5024-5030 (Link)

MXenes: new generation  of materials for environmental purposes

This research line of CompuMat involves directly with MXenes, low dimensional carbides and nitrides. In particular, we use MXenes as suitable materials for activating relevant molecules for heterogeneous catalysis and electrocatalysis such as CO2, H2, H2O or N2. Indeed, one of the most outstanding observations over MXenes is the ability for activating CO2. This generates potential usage of MXenes in the carbon capture and storage and usage (CCS/CCU). 

We use DFT based calculations to understand the kinetic mechanisms involve in relevant reactions such as the reverse water gas shift (RWGS), Fischer-Tropsch (FS), and the thermal conversion of CO2. Microkinetic and Kinetic MonteCarlo simulations are employed to identify the rate-limiting reaction step and the optical conditions at which the reaction shows the best performance. Our analysis constitutes valuabkle inputs for experimentalists. 

SOME RELATED PUBLICATIONS

Anabel Jurado, K. Ibarra, Ángel Morales-García*, F. Viñes, F. Illas. Adsorption and Activation of CO2 on Nitride MXenes: Composition, Temperature, and Pressure Effects. ChemPhysChem 2021, 22, 2456-2463 (Link) OPEN ACCESS

H. Oschinski, Ángel Morales-García*, F. Illas. Interaction of First Row Transition Metals with M2C (M=Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W) MXenes: A Quest for Single-Atom Catalysts. J. Phys. Chem. C 2021, 125, 2477-2484 (Link) OPEN ACCESS 

Ángel Morales-García, Federico Calle Vallejo and Francesc Illas. MXenes: New Horizons in Catalysis. ACS Catal. 2020, 10, 13487–13503 (Link)

Ángel Morales-García*, M. Mayans, F. Viñes, F. Illas. Thickness Biased Capture of CO2 on Carbide MXenes. Phys. Chem. Chem. Phys. 2019, 21, 23136-23142 (Link)

Ángel Morales-García, A. Fernández-Fernández, F. Viñes, F. Illas. CO2 Abatement by Two-Dimensional MXene Carbides. J. Mater. Chem. A 2018, 6, 2281-3385 (Link)

Pressure-driven the modulation of the electronic properties

Pressure, a thermodynamic variable, is employed as modulator agent to control the electronic state of semiconducting materials. In particular, the out-of-plane pressure regime emerges as the most feasible non-hydrostatic procedure to promote the semiconducting-to metal transition state.

First-principles calculations help to understand and rationalize the experimental evidences oberved by using Raman Spectroscopy. 

SOME RELATED PUBLICATIONS

A. Andrada-Chacón, Ángel Morales-García, M. Salvadó, P. Pertierra, R. Franco, G. Garbarino, M. Taravillo, J. A. Barreda-Argüeso, J. González, V. G. Baonza, J. M. Recio, J. Sánchez-Benítez. Pressure-Driven Metallization in Hafnium Diselenide. Inorg. Chem. 2021, 60, 1746-1754 (Link)

E. del Corro, M. Peña-Álvarez, K. Sato, Ángel Morales-García, M. Bousa, M. Mracko, R. Kolman, B. Pacakova, L. Kavan, M. Kalbac, O. Frank. Fine Tuning the Optical Transition Energy of Twisted Bilayer Graphene via Interlayer Distance Modulation. Phys. Rev. B 2017, 95, 085138 (Link) 

Ángel Morales-García*, E. del Corro, M. Kalbac, O. Frank. Tuning the Electronic Properties of Monolayer and Bilayer Transition Metal Dichalcogenide Compounds under Direct Out-of-Plane Compression. Phys. Chem. Chem. Phys. 2017, 19, 13333-13340 (Link) 

H. Z. Guedda, T. Ouahrani, Ángel Morales-García, R. Franco, M. A. Salvadó, P. Pertierra, J. M. Recio. Computer Simulations in 3C-SiC under Hydrostatic and Non-Hydrostatic Stresses. Phys. Chem. Chem. Phys. 2016, 18, 8132-8139 (Link)

M. Peña-Álvarez, E. del Corro, Ángel Morales-García, L. Kavan, M. Kalbac, O. Frank. Single Layer Molybdenum Disulfide under Direct Out-of-Plane Compression: Low-Stress Band-Gap Engineering. Nano Lett. 2015, 15, 3139-3146 (Link)