Title:	Atomistic Design of Hybrid Materials for Photoelectrochemical Conversion of Carbon Dioxide to Fuel
DNr:	SNIC 2015/1-354
Project Type:	SNIC Medium Compute
Principal Investigator:	Carlos Moyses Graca Araujo <moyses.araujo@kau.se>
Affiliation:	Uppsala universitet
Duration:	2015-10-01 – 2016-03-01
Classification:	10304 10407 10402
Homepage:	http://www.physics.uu.se/forskning/materialteori/medarbetare/
Keywords:

Abstract

The purpose of this research proposal is to use first-principles calculations to design novel advanced materials for application in efficient solar-energy conversion into chemical fuels. The specific aims are: (i) To achieve fundamental understanding on the photoelectrocatalytic CO2 conversion to fuel. (i) To contribute in the design of a novel photoelectrochemical catalyst made of abundant and environmentally friendly elements. We have run this project for a year now and have achieved excellent results on the underlying physics of photosensitizers (semiconductors) and also on the electrocatalysts. We have published the following papers: (i) J. M. Osorio-Guillen , W. F. Espinosa-Garcia and C. Moyses Araujo “Assessing photocatalytic power of g-C3N4 for solar fuel production: A first-principles study involving quasi-particle theory and dispersive forces” The Journal of Chemical Physics 143, 094705 (2015). (ii) Rocío Sánchez-de-Armas, Barbara Brena, Ivan Rivalta, and C. Moyses Araujo “Soft X-ray Spectroscopic Properties of Ruthenium Complex Catalyst under CO2 Electrochemical Reduction Conditions: A First-Principles Study” J. Phys. Chem. C, Articles ASAP, DOI: 10.1021/acs.jpcc.5b05626 On the continuation of the project, we will extend our study and use state of the art first-principles methods combining density functional theory (DFT) and molecular dynamics (MD) simulations. MD simulations are well suited for simulating fast processes like diffusion in liquids. However, processes with higher energy barriers, like bond-breaking chemical reactions, can be treated in a much more efficient way by the use of Kinetic Monte Carlo [1, 2]. The electronic structure at finite temperature will be evaluated by using ab initio MD simulations. Here, a sequential MD/DTF scheme will be used where some snapshots of the simulation are chosen to carry out high-accurate single point DFT calculations, and then, the obtained electronic structures are averaged. The aim is to develop a methodology that allows for direct comparison with in-situ spectroscopy measurements. Such combined experiment-theory approach can be very efficient to unveil the underlying physics at atomic scale [3]. Besides that, the simulations will also be used to evaluate the free energy of different pathways of the chemical reactions. More specifically we are interested in the photoelectrochemical conversion of CO2 catalyzed by hybrid materials made of coordinate complexes adsorbed on oxide surfaces. The latter works as photosensitizer while the former is the electrocatalyst. In this stage of the project we will focus on Ru based complexes adsorbed on C3N4 following the successful experiment of Kuriki and co-workers [4]. By unveiling the underlying catalytic mechanisms in this system we will establish the basis for a novel first-principles high throughput screening system. References: [1] L. Xu and G. Henkelman J. Chem. Phys. 129, 114104 (2008). [2] G. Henkelman, and H. Jónsson J. Chem. Phys. 115, 9657 (2001). [3] A. Hirata et al. Nature Mat. 10, 28 (2011). [4] Ryo Kuriki, Keita Sekizawa, Osamu Ishitani, and Kazuhiko Maeda Angew. Chem. Int. Ed. 54, 2406-2409 (2015).