Professor Wanderlã Luis Scopel

@article{doi:10.1021/acs.jpcc.3c03123,

title = {Bridging Borophene and Metal Surfaces: Structural, Electronic, and Electron Transport Properties},

author = {Wanderlã L. Scopel and F. Crasto de Lima and Pedro H. Souza and José E. Padilha and Roberto H. Miwa},

url = {https://doi.org/10.1021/acs.jpcc.3c03123},

doi = {10.1021/acs.jpcc.3c03123},

year  = {2023},

date = {2023-01-01},

journal = {The Journal of Physical Chemistry C},

volume = {127},

number = {35},

pages = {17556-17566},

abstract = {Currently, solid interfaces composed of two-dimensional materials (2D) in contact with metal surfaces (m-surf) have been the subject of intense research, where the borophene bilayer (BBL) has been considered a prominent material for the development of electronic devices based on 2D platforms. In this work, we present a theoretical study of the energetic, structural, and electronic properties of the BBL/m-surf interface, with m-surf = Ag(111), Au(111), and Al(111) surfaces, and the electronic transport properties of BBL channels connected to the BBL/m-surf top contacts. We find that the BBL becomes metallized due to hybridization with the metal surface states, resulting in Ohmic contacts between BBL and m-surf. However, the projected wavefunctions indicate that the inner and top-most boron layers have a weaker interaction with the m-surf, thus retaining their semiconducting character. The net charge transfers reveal that BBL has become n-type (p-type) doped for m-surf = Ag and Al (= Au). A thorough structural characterization of the BBL/m-surf interface, using a series of simulations of X-ray photoelectron spectra, shows that the formation of the BBL/m-surf interface is characterized by a red shift of the B-1s spectra. Further electronic transport results revealed the emergence of a Schottky barrier between 0.1 and 0.2 eV between the BBL/m-surf contact and the BBL channels. We believe that our findings are timely, bringing important contributions to the applicability of BBLs for developing 2D electronic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{D2CP03666E,

title = {Combined computational and experimental study about the incorporation of phosphorus into the structure of graphene oxide},

author = {Tainara L. G. Costa and Mariana A. Vieira and Gustavo R. Gonçalves and Daniel F. Cipriano and Valdemar Lacerda and Arlan S. Gonçalves and Wanderlã L. Scopel and Abner Siervo and Jair C. C. Freitas},

url = {http://dx.doi.org/10.1039/D2CP03666E},

doi = {10.1039/D2CP03666E},

year  = {2023},

date = {2023-01-01},

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

volume = {25},

issue = {9},

pages = {6927-6943},

publisher = {The Royal Society of Chemistry},

abstract = {Phosphorus-containing graphene-based hybrids are materials with outstanding properties for diverse applications. In this work, an easy route to produce phosphorus-graphene oxide hybrid materials is described, involving the use of variable amounts of H3PO4 and H2SO4 during the reaction of oxidation of a graphitic precursor. The physical and chemical features of the hybrids change significantly with the variation in the acid amounts used in the syntheses. XPS and solid-state 13C and 31P NMR results show that the hybrids contain large amounts of oxygen functional groups, with the phosphorus incorporation proceeding mostly through the formation of phosphate-like linkages and other functions with C–O–P bonds. The experimental findings are supported by DFT calculations, which allow the assessment of the energetics and the geometry of the interaction between phosphate groups and graphene-based models; these calculations are also used to predict the chemical shifts in the 31P and 13C NMR spectra of the models, which show good agreement with the experimentally observed solid-state NMR spectra.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{SILVEIRA2023122570,

title = {A comprehensive study of the reduction of nitrate on natural FeTiO3: Photocatalysis and DFT calculations},

author = {Jefferson E. Silveira and Aramille S. Souza and Fernando N. N. Pansini and Alyson R. Ribeiro and Wanderlã L. Scopel and Juan A. Zazo and Jose A. Casas and Wendel S. Paz},

url = {https://www.sciencedirect.com/science/article/pii/S1383586622021268},

doi = {https://doi.org/10.1016/j.seppur.2022.122570},

issn = {1383-5866},

year  = {2023},

date = {2023-01-01},

journal = {Separation and Purification Technology},

volume = {306},

pages = {122570},

abstract = {Experimental and theoretical investigation of the capacity of the natural ilmenite (FeTiO3) to reduce nitrate (NO3−) from ultra-pure and mineral water is presented. A comprehensive mechanism of NO3− photocatalytic transformation is proposed regarding the density functional theory (DFT) calculations and the photocatalytic reduction of nitrate. When ultra-pure water is employed, the nitrate is totally converted to NOX (2%) and N2 (98%) after 210 min. Additionally, using the stoichiometric dose of oxalate, the nitrate also vanishes from the mineral water, forming NO2−, NOX, and N2 as products. Thus, the findings reveal that natural ilmenite can be a great candidate for reducing NO3− in contaminated water.},

keywords = {DFT, Ilmenite, Nitrate, Photoreduction},

pubstate = {published},

tppubtype = {article}

}

@article{AMBROZIO2023100091,

title = {Combined experimental and computational 1H NMR study of water adsorption onto graphenic materials},

author = {Alan R. Ambrozio and Thierry R. Lopes and Daniel F. Cipriano and Fábio A. L. Souza and Wanderlã L. Scopel and Jair C. C. Freitas},

url = {https://www.sciencedirect.com/science/article/pii/S2666441022000619},

doi = {https://doi.org/10.1016/j.jmro.2022.100091},

issn = {2666-4410},

year  = {2023},

date = {2023-01-01},

journal = {Journal of Magnetic Resonance Open},

volume = {14-15},

pages = {100091},

abstract = {The effects caused by the interaction with graphene-like layers on the 1H NMR spectra of water molecules adsorbed onto porous carbon materials were investigated by a combination of shielding calculations using density functional theory (DFT) and 1H NMR experiments. Experimental 1H NMR spectra were recorded for different water-containing carbon materials (activated carbons and milled graphite samples); the 1H NMR signals due to adsorbed water in these materials showed a strong shielding effect caused by the electron currents present in the graphene-like layers. This effect was enhanced for activated carbons prepared at high heat treatment temperatures and for milled graphite samples with short milling times, evidencing that the structural organization of the graphene-like layers was the key feature defining the magnitude of the shielding on the 1H nuclei in the water molecules adsorbed by the analyzed materials. The DFT calculations of the shielding sensed by these 1H nuclei showed an increased interaction with the graphitic layers as the distance between these layers (representing the pore size) was reduced. A continuous decrease of the 1H NMR chemical shift was then predicted for pores of smaller sizes, in good agreement with the experimental findings. These calculations also showed a large dispersion of chemical shifts for the several 1H nuclei in the water clusters, attributed to intermolecular interactions and to shielding variations within the pores. This dispersion, combined with the effects due to the locally anisotropic diamagnetic susceptibility of graphite-like crystallites, are the main contributions to the broadening of the 1H NMR signals associated with water adsorbed onto porous carbon materials.},

keywords = {DFT, Graphenic materials, H NMR, Water adsorption},

pubstate = {published},

tppubtype = {article}

}