Professor Rodrigo Garcia Amorim

@article{Kaewmaraya2025,

title = {Highly efficient room-temperature ethylene sensing with molybdenum based transition metal dichalcogenides},

author = {T. Kaewmaraya and Rodrigo G. Amorim and N. Thatsami and P. Moontragoon and S. Pinitsoontorn and H. Bae and H. Lee and N. Nasiri and T. Hussain},

doi = {10.1016/j.apsusc.2025.162984},

issn = {0169-4332},

year  = {2025},

date = {2025-07-00},

urldate = {2025-07-00},

journal = {Applied Surface Science},

volume = {697},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Spalenza2025,

title = {Fast recovery and ultrasensitive net-graphene sensor for monitoring SF
author = {Pedro Elias Priori Spalenza and Fábio Arthur Leão de Souza and Rodrigo G. Amorim and César E.P. Villegas and Ravindra Pandey and Wanderlã L. Scopel},

doi = {10.1016/j.apsusc.2025.163006},

issn = {0169-4332},

year  = {2025},

date = {2025-03-30},

urldate = {2025-07-00},

journal = {Applied Surface Science},

volume = {698},

publisher = {Elsevier BV},

abstract = {Power industry insulator sulfur hexafluoride (SF) has excellent dielectric properties. However, SF decomposes into by-products over time, making their detection essential for power device evaluation and fault prevention. Recently, 2D materials, especially carbon-based ones, have become excellent gas sensing platforms, expected to lead the next generation of sensors. Because graphitic materials and SF decomposition products have weak van der Waals interactions, functionalization has been the most promising way to improve surface-molecule interactions, but it also presents experimental challenges. We propose monitoring SF degradation with a pristine net-graphene nanosensor to address these issues. Here, density functional theory and non-equilibrium Green’s functions methods are used to study the interaction between net-graphene device and gas-insulated switchgear atmosphere gas (SF, CO, N, H2O, and O), as well as the decomposition products of SF. These molecules are physisorbed on net-graphene, causing p-type doping in the device. The system’s conductance is modulated by molecule-net-graphene interactions, allowing target molecule detection and identification. We propose a field-effect device that can sense SO and HS without cross-selectivity and with a fast recovery time. It is also resistant to O and HO degradation. We found that net-graphene is a promising nanomaterial for real-time monitoring of power industry SF decomposition by-products.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{NarcisoPedrosa2025,

title = {Interlayer Excitons and Radiative Lifetimes in MoSe2/SeWS Bilayers: Implications for Light-Emitting Diodes},

author = {Renan Narciso Pedrosa and Cesar E. P. Villegas and Alexandre Reily Rocha and Rodrigo G. Amorim and Wanderlã L. Scopel},

url = {https://pubs.acs.org/doi/full/10.1021/acsanm.4c06994},

doi = {10.1021/acsanm.4c06994},

issn = {2574-0970},

year  = {2025},

date = {2025-03-14},

urldate = {2025-03-14},

journal = {ACS Appl. Nano Mater.},

volume = {8},

number = {10},

pages = {5051--5058},

publisher = {American Chemical Society (ACS)},

abstract = {Interlayer excitons, formed by electrical charge transfer between layers of 2D van der Waals heterostructures, are of the utmost importance for light-detection and light-harvesting applications. In particular, Janus-based heterostructures are promising platforms to observe robust interlayer exciton dynamics due to their intrinsic electric field. Here, we carry out ground- and excited-state first-principles calculations, based on the G0W0 approach and the solution of the Bethe–Salpeter equation, to investigate the energetic, electronic, and excitonic properties of MoSe2/WSSe van der Waals heterobilayers. Our results show that the heterojunction presents features of type-II band alignment and tightly bound, long-lived interlayer excitons. Indeed, the lowest dipole-allowed excitonic state possesses an interlayer character and a slight deviation of 12% in its binding energy compared to the lowest-energy intralayer exciton. Furthermore, the interlayer excitons have transition rates ∼55 times smaller than the intralayer ones, which translates into a longer radiative lifetime of dozens of nanoseconds at room temperature. This is up to 2 orders of magnitude greater than that of the lowest-energy intralayer exciton. The findings emphasize the critical role of Janus-based heterojunctions in influencing interlayer exciton radiative lifetimes, indicating that the system possesses considerable potential for application in optoelectronic devices such as a light-emitting diode (LED) or photodetector.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Scopel2025,

title = {Computational simulation of graphene/h-BN nanopores for single-molecule herbicide sensing},

author = {Wanderlã L. Scopel and Fábio A. L. de Souza and Sávio Bastos de Souza and Rodrigo G. Amorim and Ralph H Scheicher},

url = {https://pubs.rsc.org/th/content/articlelanding/2025/nr/d4nr03359k},

doi = {10.1088/1361-6528/adac67},

issn = {1361-6528},

year  = {2025},

date = {2025-01-21},

urldate = {2025-01-21},

journal = {Nanotechnology},

publisher = {IOP Publishing},

abstract = {The growing world population and climate change are key drivers for the increasing pursuit of more efficient and environmentally-safe food production. In this scenario, the large scale use of herbicides demands the development new technologies to control
and monitor the application of these compounds, due to their several environmental and health-related problems. Motivated by all these issues, in this work, a hybrid graphene/boron nitride nanopore is explore to detect/identify herbicide molecules (Glyphosate, AMPA, Diuron, and 2,4-D). Solid-state nanopores based on 2D materials have been widely explored as novel generation sensors capable of single-molecule resolution. The present investigation combines the density functional theory (DFT) and non-equilibrium Green’s function (NEGF) method to assess the interaction of each herbicide with the nanopore and how its interaction modulates the device’s electronic
transport properties. The device’s sensitivity spreads from 9.0 up to 27.0% when probed at different gate voltage values. Overall, the proposed device seems to be sensitive and selective to be considered as a promising single-molecule herbicide sensor.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Amorim2025,

title = {Detection and distinction of amino acids and post-translational modifications with gold nanojunctions},

author = {Rodrigo G. Amorim and Filipe C. D. A. Lima and Fábio Arthur Leão de Souza and Wanderlã L. Scopel and Jariyanee Prasongkit and Ralph H. Scheicher},

url = {https://pubs.rsc.org/th/content/articlelanding/2025/nr/d4nr03359k},

doi = {10.1039/d4nr03359k},

issn = {2040-3372},

year  = {2025},

date = {2025-01-01},

urldate = {2025-01-01},

journal = {Nanoscale},

publisher = {Royal Society of Chemistry (RSC)},

abstract = {Amino acids are fundamental building blocks of proteins, playing critical roles in medical diagnostics, environmental monitoring, and biomarker identification. The development of nanoscale electronic sensors capable of single-amino-acid recognition has gained significant attention due to their potential for label-free, real-time detection. In this study, we investigate the electronic transport properties of amino acids in two gold-based nanodevices with distinct architectures: a gold nanojunction and a gold-capacitor system. Using density functional theory (DFT) in combination with nonequilibrium Green's function (NEGF) calculations, we explore the sensing mechanism and conductance variations induced by different amino acids, including select phosphorylated variants. Each device was assigned a reference amino acid, F (M), for a capacitor (nanojunction) to differentiate its conductance from other molecules. Our results reveal distinct conductance that enables amino acid classification based on their electronic signatures, demonstrating that molecular discrimination is primarily governed by conductance variations as a function of the binding energy differences. The nanojunction exhibited remarkable differentiation for the amino acids S, pS, Y, and pY, rendering it especially proficient in distinguishing between structurally analogous molecules. These findings highlight the strong potential of gold-based nanodevices for precise amino acid detection, paving the way for advancements in biosensing technologies, molecular diagnostics, and biomedical applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{spalenza2024high,

title = {High density nanopore 3-triangulene kagome lattice},

author = {Pedro Spalenza and Fábio AL Souza and Rodrigo G. Amorim and Ralph H Scheicher and Wanderlã L. Scopel},

url = {https://pubs.rsc.org/en/content/articlehtml/2024/nr/d4nr00910j},

doi = {10.1039/D4NR00910J },

year  = {2024},

date = {2024-04-11},

urldate = {2024-01-01},

journal = {Nanoscale},

publisher = {Royal Society of Chemistry},

abstract = {Nanopore-containing two-dimensional materials have been explored for a wide range of applications including filtration, sensing, catalysis, energy storage and conversion. Triangulenes have recently been experimentally synthesized in a variety of sizes. In this regard, using these systems as building blocks, we theoretically examined 3-triangulene kagome crystals with inherent holes of ∼12 Å diameter and a greater density array of nanopores (≥1013 cm−2) compared to conventional 2D systems. The energetic, electronic, and transport properties of pristine and B/N-doped 3-triangulene kagome crystals were evaluated through a combination of density functional theory and non-equilibrium Green's function method. The simulated scanning tunneling microscopy images clearly capture electronic perturbation around the doped sites, which can be used to distinguish the pristine system from the doped systems. The viability of precisely controlling the band structure and transport properties by changing the type and concentration of doping atoms is demonstrated. The findings presented herein can potentially widen the applicability of these systems that combine unique electronic properties and intrinsically high-density pores, which can pave the way for the next generation of nanopore-based devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{moraes2024high,

title = {High Efficiency of Myclobutanil Adsorption by CTAB-zeolite Structures: Experimental Evidence Meets Theoretical Investigation},

author = {Caio S Moraes and Patrícia A Carneiro and Diêgo N Faria and Daniel F Cipriano and Jair CC Freitas and Rodrigo G. Amorim and Ramon S Silva and Mendelssolm K Pietre},

url = {https://link.springer.com/article/10.1007/s12633-024-02950-9},

doi = {doi.org/10.1007/s12633-024-02950-9},

year  = {2024},

date = {2024-03-25},

urldate = {2024-03-25},

journal = {Silicon},

pages = {1–17},

publisher = {Springer},

abstract = {Pesticides effectively manage fungal diseases in fruits and vegetables; however, their toxicity poses significant environmental risks to human beings. Consequently, the chemical industry faces a daunting challenge in controlling or eliminating the presence of pesticides in the natural environment. The present work reports the synthesis of zeolitic materials with distinct structural properties (starting from the layered precursor PREFER and 3D-faujasite) and their use for the removal of the pesticide myclobutanil. The PREFER sample underwent two distinct treatments: external functionalization with CTAB and layers separation (delamination). On the other hand, external functionalization of the faujasite surface with different CTAB contents was performed. The results showed that the potentially delaminated PREFER sample (PREFER-CTAB-90ºC) performed better in removing the pesticide among all the samples due to the higher availability of CTAB on their exposed lamellae. In contrast, the samples with a double-layered arrangement of CTAB chains presented better pesticide removal performance in comparison with the samples with a single CTAB arrangement. DFT calculations were performed to elucidate the interaction mechanism occurring between myclobutanil and CTAB. The obtained results indicate that the adsorption of myclobutanil by two CTAB molecules is more efficient than a single CTAB; the calculated binding energy considering two CTAB molecules in the process was nearly four times larger than for a single CTAB. The theoretical data provided validation for the adsorbent performances, including a detailed discussion of molecular mechanisms (with and without solvent effects). This proof-of-principle study emphasizes the significant potential of CTAB-functionalized zeolite in removing myclobutanil. This represents an important advancement toward better understanding and harnessing the capabilities of this material for effective and efficient pesticide removal.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pedrosa2024optical,

title = {Optical properties enhancement via WSSe/silicene solar cell junctions},

author = {Renan Narciso Pedrosa and Cesar EP Villegas and Alexandre Reily Rocha and Rodrigo G. Amorim and Wanderlã L. Scopel},

url = {https://pubs.rsc.org/en/content/articlehtml/2024/ya/d3ya00529a},

doi = {10.1039/D3YA00529A},

year  = {2024},

date = {2024-03-04},

urldate = {2024-03-04},

journal = {Energy Advances},

volume = {3},

number = {4},

pages = {821–828},

publisher = {Royal Society of Chemistry},

abstract = {2D Janus monolayers exhibit nanoscale asymmetric surface organization along the out-of-plane direction and have recently emerged as a class of 2D materials. In this work, we investigate the energetic, electronic, and optical properties of the vertical van der Waals stack between WSSe and silicene monolayers based on first-principles calculations. The Janus/silicene interface formation is driven by an exothermic process, and charge transfer from the silicene to the Janus monolayer is observed. The intrinsic properties of silicene and Janus are preserved despite the stacking of the parts. The Bethe–Salpeter equation (BSE) was used to understand the contact influence on the optical absorption spectrum of the vertical interface. Our findings reveal that the power conversion energy (PCE) of the heterostructure is boosted 2.42 times higher than that of the Janus monolayer. Thus, due to its PCE and transparent electrical contact, the heterojunction is a promising candidate for use as a photovoltaic device compared to its counterparts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{D3CP05358J,

title = {Boron-Doped Graphene Topological Defects: Unveiling High Sensitivity to NO Gas Molecules for Gas Sensing Applications},

author = {B. Keshav Rao and Tadeu Luiz Gomes Cabral and Debora Carvalho de Melo Rodrigues and Fábio Arthur Arthur Leão de Souza and Wanderlã L. Scopel and Rodrigo G. Amorim and Ravi Pandey},

url = {http://dx.doi.org/10.1039/D3CP05358J},

doi = {10.1039/D3CP05358J},

year  = {2024},

date = {2024-01-03},

urldate = {2024-01-03},

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

pages = {-},

publisher = {The Royal Society of Chemistry},

abstract = {Global air quality has deteriorated significantly in recent years due to factors such as a large number of combustion cars and the transformation industry. This issue presents great opportunities for developing a new category of gas sensors that are highly sensitive and selective. In this paper, we consider B-doped graphene consisting of a 5-5-8 line defect to assess its sensitivity to various gas molecules such as CO, CO2, NO, and NH3. Calculations based on the density functional theory find that the B dopant is energetically stable and leads to p-type doping in the lattice. Theoretical Scanning Tunneling Microscopy image has generated defect fingerprints that show a distinct bright spot at the dopant site, distinguishing it from those observed for the defective graphene. The results predict the defective B-doped graphene to be metallic, which displays a preference for binding with NO and NH3 over CO and CO2 molecules. The charge transfer between the molecule and monolayer differs in the cases of physisorbed CO/CO2 and chemisorbed NO/NH3. The electron transport calculations based on the non-equilibrium Green’s Function method predict a relatively high level of sensitivity for the NO molecule relative to the other molecules considered. The calculated recovery time agrees with the experimental results at room temperature for NH3 at visible and for NO at UV radiation. Finally, the results establish B-doped defective graphene as a highly promising material for NO gas sensors at the nanoscale.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{D3CP05358Jb,

title = {Boron-doped graphene topological defects: unveiling high sensitivity to NO molecule for gas sensing applications},

author = {B. Keshav Rao and Tadeu Luiz Gomes Cabral and Debora Carvalho de Melo Rodrigues and Fábio A. L. Souza and Wanderlã L. Scopel and Rodrigo G. Amorim and Ravindra Pandey},

url = {http://dx.doi.org/10.1039/D3CP05358J},

doi = {10.1039/D3CP05358J},

year  = {2024},

date = {2024-01-03},

urldate = {2024-01-01},

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

volume = {26},

issue = {5},

pages = {4466-4473},

publisher = {The Royal Society of Chemistry},

abstract = {Global air quality has deteriorated significantly in recent years due to large emissions from the transformation industry and combustion vehicles. This issue requires the development of portable, highly sensitive, and selective gas sensors. Nanostructured materials, including defective graphene, have emerged as promising candidates for such applications. In this work, we investigated the B-doped topological line defect in graphene as a sensing material for various gas molecules (CO, CO2, NO, and NH3) based on a combination of density functional theory and the non-equilibrium Green's function method. The electronic transport calculations reveal that the electric current can be confined to the line defect region by gate voltage control, revealing highly reactive sites. The B-doped topological line defect is metallic, favoring the adsorption of NO and NH3 over CO and CO2 molecules. We notice changes in the conductance after gas molecule adsorption, producing a sensitivity of 50% (16%) for NO (NH3). In addition, the recovery time for nitride gases was calculated for different temperatures and radiation frequencies. At 300 K the ultraviolet (UV) has a fast recovery time compared to the visible (VIS) one by about two orders of magnitude. This study gives an understanding of how engineering transport properties at the microscopic level (by topological line defect and chemical B-doping) leads to promising nanosensors for detecting nitride gas.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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}

}