We make the best out of the heterogeneity in nanomaterials.
The presence of defects in nanomaterials is more of a rule than an exception. So why not taking it to the extreme? Highly defective nanomaterials can be quite exotic, their components often exhibit variable oxidation states and coordination environment, and they might contain both amorphous and crystalline phases. The stoichiometry of largely defective materials can be significantly altered, and possibly new and interesting physical and chemical properties might arise. The importance of non-stoichiometric materials lies in their ability to stabilize elements in unusual oxidation states, or even stabilize exotic crystal phases at the junction of others. All these provides a variety of knobs to tune the materials physical and chemical properties.
Eduardo Gracia, in the middle, with his research group memebers.
Our experimental work is aimed at producing heterogeneous and defect-rich nanomaterials containing a large diversity of structural defects, such as vacancies, grain boundaries, interfaces, and doping. We work with a variety of low-dimensional materials, including nanocarbons, layered metal dichalcogenides, binary and ternary metal nanoparticles, and multicomponent metal oxides. Nowadays, we aim at developping synthesis techniques suitable for a rapid nanomaterial production and characterization to accelerate the material discovery. We also develop theoretical tools to investigate at the atomic level how heterogeneity in nanomaterials affect their properties, and we introduced the use of catalytic activity maps to observe the variation in catalytic activity due to the presence of defects. This combinatory approach of theory and experiment allows us to study materials at different length scales from the atomic level up to the macroscopic world.
Our research leads to a better understanding of highly defective multi-component nanomaterials, and our results have been applied to develop electrocatalysts, chemical barriers, and functional coatings.