Maicon Pierre Lourenço

Universidade Federal do Espírito Santo | UFES · Química e Física

Ni‐CeO 2 nanoparticles (NPs) are promising nanocatalysts for water splitting and water gas shift reactions due to the ability of ceria to temporarily donate oxygen to the catalytic reaction and accept oxygen after the reaction is completed. Therefore, elucidating how different properties of the Ni‐Ceria NPs relate to the activity and selectivity of...

Reinforcement learning (RL) methods have helped to define the state of the art in the field of modern artificial intelligence, mostly after the breakthrough involving AlphaGo and the discovery of novel algorithms. In this work, we present a RL method, based on Q‐learning, for the structural determination of adsorbate@substrate models in silico, whe...

Inspired by the successful transfer of freestanding ultrathin films of SrTiO3 and BiFeO3 onto various substrates without any thickness limitation, in this study, using density functional theory (DFT), we assessed the structural stability of a group of two-dimensional perovskite-type materials which we call perovskenes. Specifically, we analyzed the...

Since the form of the exact functional in density functional theory is unknown, we must rely on density functional approximations (DFAs). In the past, very promising results have been reported by combining semi-local DFAs with exact, i.e. Hartree–Fock, exchange. However, the spin-state energy ordering and the predictions of global minima structures...

Structural elucidation of chemical compounds is challenging experimentally, and theoretical chemistry methods have added important insight into molecules, nanoparticles, alloys, and materials geometries and properties. However, finding the optimum structures is a bottleneck due to the huge search space, and global search algorithms have been used s...

Strawberry is a food rich in bioactive compounds with great antioxidant potential. However, due to the high incidence of pests that affect crop cultivation, phytosanitary management still lacks control methods for agroecological cultivation. Thus, the present research aimed to evaluate the chemical composition and the potential of the essential oil...

Finding the optimum material with improved properties for a given application is challenging because data acquisition in materials science and chemistry is time consuming and expensive. Therefore, dealing with small datasets is a reality in chemistry, whether the data are obtained from synthesis or computational experiments. In this work, we propos...

Euterpe edulis Martius is an endangered species of the Atlantic Forest, whose fruits have high antioxidant potential, and propagated exclusively by seeds. The present study assessed the ability of different auxin inducers and picloram analogs to trigger somatic embryogenesis in E. edulis . Immature seeds were harvested, and their zygotic embryos we...

Genetic algorithms (GAs) are stochastic global search methods inspired by biological evolution. They have been used extensively in chemistry and materials science coupled with theoretical methods, ranging from force‐fields to high‐throughput first‐principles methods. The methodology allows an accurate and automated structural determination for mole...

Finding the optimum structures of non-stoichiometric or berthollide materials, such as (1D, 2D, 3D) materials or nanoparticles (0D), is challenging due to the huge chemical/structural search space. Computational methods...

Drinking water is a vital resource for the population’s quality of life and health. The satisfaction of their needs is increasingly demanding, essentially associated with the growth of the population's income and the possibility of improvements in terms of comfort, quality, and safety at lower costs. However, despite the accuracy of engineering des...

Adsorbate interactions with substrates (e.g. surfaces and nanoparticles) are fundamental for several technologies, such as functional materials, supramolecular chemistry, and solvent interactions. However, modeling these kinds of systems in silico, such as finding the optimum adsorption geometry and energy, is challenging, due to the huge number of...

Employing first-principles calculations based on density functional theory (DFT), we designed a novel two-dimensional (2D) elemental monolayer allotrope of carbon called hexatetra-carbon. In the hexatetra-carbon structure, each carbon atom bonds with its four neighboring atoms in a 2D double layer crystal structure, which is formed by a network of...

Herbicides are agrochemicals applied in the control of weeds. With the frequent and repetitive use of these substances, serious problems have been reported. Compounds of natural origin and their derivatives are attractive options to obtain new compounds with herbicidal properties. By aiming to develop compounds with potentiated herbicidal activity,...

Active learning (AL) has been successfully applied in materials science for the global optimization of clusters and defects in materials. Many important chemistry problems require the structural elucidation of molecules as a first step to the mechanistic elucidation of complex heterogeneous catalysis phenomena. Theoretical methods coupled with glob...

In catalysis, an accurate structural elucidation of molecules, atomic clusters, nanoparticles and solid surfaces is required to understand chemical processes. Therefore, an efficient and automatic structure determination for these systems is of great benefit since it requires a global search within huge chemical spaces. In this work, we propose a n...

The study of materials in the nanoscale regime has important applications for catalytic reactions, the energy industry and medicine. We performed exploratory density functional theory calculations for molybdenum disulphide (MoS2) and calcium carbonate (CaCO3) nanoparticles (NPs), the former being developed as a hydrogenation and coke-prevention cat...

In this work, we explore the possibility of using computationally inexpensive electronic structure methods, such as semiempirical and DFTB calculations, for the search of the global minimum (GM) structure of chemical systems. The basic prerequisite that these inexpensive methods will need to fulfill is that their lowest energy structures can be use...

Designing and understanding the mechanism of non-stoichiometric materials with enhanced properties is challenging, both experimentally and even computationally, due to the large number of chemical spaces and their distributions through the material. In the current work, it is proposed a Machine Learning approach coupled with the Efficient Global Op...

The SCC-DFTB repulsion parameters based on the Material Science set (matsci) were redesigned to describe the structure and dynamic properties of bulk liquid water. The Iterative Boltzman Inversion (IBI) approach was applied by simultaneously correcting the O-H and O-O SCC-DFTB repulsion energy contribution to develop the new water-matsci and water-...

Oxide-derived copper (OD-Cu) catalysts are promising candidates for the electrochemical CO2 reduction reaction (CO2RR) due to the enhanced selectivity towards ethylene over methane evolution, which has been linked to the presence of subsurface oxygen (Osb). In this work, Osb is investigated with theoretical methods. Although Osb is unstable in slab...

Pyrite is the most common sulfide in the Earth, and in the presence of arsenopyrite its oxidation is delayed and instead the arsenopyrite increases its oxidation rate, releasing As(III) and As(V) species in the medium. DFT/plane waves calculations were performed on Pyrite/Arsenopyrite interface models to understand the stability, structure, and ele...

The self-consistent-charge density-functional tight-binding method (SCC-DFTB) is largely used for investigating systems of increasing complexity. However, the SCC-DFTB parameters are not available for the whole periodic table and some issues related to its transferability can limit its usefulness. The framework for automating the repulsion energy (...

Imogolites (aluminosilicate and aluminogermanate) are nanotubes (NTs) with well-defined diameter and chirality that can be synthesized in aqueous solution in mild conditions. It has been shown that the diameter and the single- or double-walled NT formation can be controlled depending on the synthesis parameters such as anionic ligands, temperature,...

The electronic, structural and mechanical properties of the modified imogolites have been investigated using self consistent charge-density functional-tight binding method with “a posteriori” treatment of the dispersion interaction (SCC-DFTB-D). The zigzag (12,0) imogolite has been used as the initial structure for the calculations. The functionali...

We have investigated the structure and electronic structure of single- and double-walled imogolite nanotubes with Ge and Si as group IV element. While it is known from experiment, and in the case of single-walled tubes confirmed by theory, imogolite nanotubes are monodisperse in diameter. We show that imogolite tubes are also showing a preferred ch...

The aim of this work was to study the interaction between the local anesthetic benzocaine and p-sulfonic acid calix[n]arenes using NMR and theoretical calculations and to assess the effects of complexation on cytotoxicity of benzocaine. The architectures of the complexes were proposed according to (1) H NMR data (Job plot, binding constants and ROE...

Imogolite is a single-walled aluminosilicate nanotube (NT) found in nature that can be easily synthesized, as well as its analogue aluminogermanate NT. Based on geometrical assumptions and pKa values, species such as HPO, HPO, HAsO, HAsO could also be candidates to form imogolite-like structures. In the present work, we provide insights about the s...

Self-consistent-charge density-functional tight-binding (SCC-DFTB) approximated method was employed to investigate the structural, mechanical and electronic properties of the zigzag and armchair nano-fibriform silica (SNTs) and their outer surface organic modified derivatives (MSNTs) with internal radii in the range of 8 to 36 Å. The strain energy...

Structural, electronic, and mechanical properties of single-walled chrysotile nanotubes have been investigated using the self-consistent charge density-functional tight-binding method (SCC-DFTB). The naturally occurring chrysotile nanotubes (NTs) are composed of brucite, Mg(OH)2, layer in the outer side and tridymite, SiO2, in the inner side. The z...