Professor Rodrigo Garcia Amorim

@article{D3CP04267G,

title = {Topological Line Defects in Hexagonal SiC Monolayer},

author = {Wallace P. Morais and Guilherme Janone Inacio and Rodrigo G. Amorim and Wendel Silva Paz and Fernando Nespoli Nassar Pansini and Fábio Arthur Arthur Leão de Souza},

url = {http://dx.doi.org/10.1039/D3CP04267G},

doi = {10.1039/D3CP04267G},

year  = {2023},

date = {2023-11-21},

urldate = {2023-01-01},

journal = {Phys. Chem. Chem. Phys.},

pages = {-},

publisher = {The Royal Society of Chemistry},

abstract = {Defect engineering of two-dimensional (2D) materials offer an unprecedented route to increase their functionality and broaden their applicability. In light of the recent synthesis of the 2D Silicon Carbide (SiC), a deep understanding of the effect of defects on the physical and chemical properties of this new SiC allotrope becomes highly desirable. This study investigates 585 extended line defects (ELDs) in hexagonal SiC considering three types of interstitial atom pairs (SiSi-, SiC-, and CC-ELD) and using computational methods like Density Functional Theory, Born-Oppenheimer Molecular Dynamics, and Kinetic Monte-Carlo (KMC). Results show that the formation of all ELD systems is endothermic, with the CC-ELD structure showing the highest stability at 300 K. To further characterize the ELDs, simulated Scanning Tunneling Microscopy (STM) is employed, and successfully allow identify and distinguish the three types of ELDs. Although pristine SiC has a direct band gap of 2.48 eV, the presence of ELDs introduces mid-gap states derived from the $p_z$ orbitals at the defect sites. Furthermore, our findings reveal that the ELD region displays enhanced reactivity towards hydrogen adsorption, which was confirmed by KMC simulations. Overall, this research provides valuable insights into the structural, electronic, and reactivity properties of ELDs in hexagonal SiC monolayers and paves the way for potential applications in areas such as catalysis, optoelectronics, and surface science.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RODRIGUES2023118087,

title = {Improving the sensitivity of graphyne nanosensor by transition metal doping},

author = {Debora C. M. Rodrigues and Rodrigo G. Amorim and A. Latgé and Pedro Venezuela},

url = {https://www.sciencedirect.com/science/article/pii/S0008622323003329},

doi = {https://doi.org/10.1016/j.carbon.2023.118087},

issn = {0008-6223},

year  = {2023},

date = {2023-01-01},

journal = {Carbon},

volume = {212},

pages = {118087},

abstract = {The concern with air quality and safety urges for design and development of new gas sensors. Graphyne presents comparable electronic mobility and mechanical properties to graphene, with the advantage of naturally allowing single-atom dispersion into acetylenic pores. Therefore, we investigate the detection ability of transition metal (TM: Fe and Ni) doped graphyne (Gy) toward CO, NO, NO2, and CO2 gas molecules. Our aim is to engineer the electronic characteristics and further improve the sensing properties. We model the sensing device using TM-doped Gy nanoribbons (TM-GyNR) using density functional theory combined with non-equilibrium Green’s functions. Most of the gases presented chemical adsorption on the TM-GyNR, with slightly weaker interaction for gas/NiGyNR systems than gas/FeGyNR. These differences produced recovery times compatible with room temperature detectors for CO and NO (NiGyNR) and CO2 (FeGyNR) gases. We obtain gas sensitivity as high as 117% for CO/FeGyNR and 300% for NO2/NiGyNR. Due to mutual differences in binding energies and sensitivity among the gases, NiGyNR and FeGyNR also present high selectivity to distinguish the target molecules. Finally, our findings suggest that TM functionalization of graphynes is a promising strategy for engineering the sensitivity of gas nanosensors.},

keywords = {DFT, Electronic transport, Gas sensor, Graphyne, Transition metal},

pubstate = {published},

tppubtype = {article}

}

@article{VOVUSHA2023101543,

title = {Sensing of sulfur containing toxic gases with double transition metal carbide MXenes},

author = {H. Vovusha and Rodrigo G. Amorim and H. Bae and S. Lee and T. Hussain and H. Lee},

url = {https://www.sciencedirect.com/science/article/pii/S2468519423001702},

doi = {https://doi.org/10.1016/j.mtchem.2023.101543},

issn = {2468-5194},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Materials Today Chemistry},

volume = {30},

pages = {101543},

abstract = {Sensing of sulfur containing gases, such as hydrogen sulfide (H2S) and sulfur dioxide (SO2), on double transition metal carbide MXenes has been studied by means of density functional theory calculations. It is found that both H2S and SO2 strongly physisorbed on M2TiC2Tx (M = Mo, Cr; Tx = O, S, OH) monolayers. The adsorption of H2S is stronger in the case of oxygen termination, (Mo2TiC2O2, Cr2TiC2O2), whereas SO2 has stronger adsorption on sulfur terminated (Mo2TiC2S2, Cr2TiC2S2) monolayers. Binding characteristics of H2S and SO2 are further confirmed with Bader charge transfer, density of states, and charge density differences. Using a statistical thermodynamic analysis, the sensing mechanism of H2S and SO2 is studied under varied pressures and temperature conditions. By means of non-equilibrium Green's function calculations, the sensitivities of H2S and SO2 on the Mo2TiC2S2 monolayer are found to be 16.3%, 10.3%, respectively, which showed promising sensing characteristics. Our results reveal that double transition metal carbide MXenes can be a potential candidate for the sensing of sulfur containing gases.},

keywords = {Adsorption, Double MXenes, Green's functions, Sulfur containing gases, Thermodynamic analysis},

pubstate = {published},

tppubtype = {article}

}