RODRIGO FERNANDO BRAMBILLA DE SOUZA

RODRIGO FERNANDO BRAMBILLA DE SOUZA

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Nickel supported on polymeric graphitic carbon nitride for electrocatalytic in reduction of carbon dioxide
2023 - BATISTA, WALKER V.F. do C.; COELHO, JESSICA F.; OLIVEIRA, WANESSA L. de; PEREIRA FILHO, NIVALDO G.; OLIVEIRA, EDUARDA F. de; CRUZ, TAIS dos S. da; SILVA, HIDILA S.T. da; MARQUES, GLEISON N.; MESQUITA, JOAO P. de; SOUZA, RODRIGO F.B. de; NETO, ALMIR O.
This study explores the potential of carbon-based materials, specifically CN-Ni-doped, as catalysts for CO2 reduction to methanol in a PEM-R. The research investigates the impact of Ni incorporation on CN's structure, resulting in increased interlayer spacing and reduced crystallite size. Additionally, the introduction of Ni modifies the samples' morphology, creating a more compact structure with smaller sheets. The findings indicate that CN-Ni displays promising catalytic activity, achieving a 25% Faradaic Efficiency (FE) with a methanol production rate of approximately 1.1 mol L−1 h−1. The study underscores the significance of optimizing reactor operational parameters to enhance CO2RR. In conclusion, this research contributes to the advancement of efficient and sustainable approaches for CO2 utilization and methanol synthesis.
Application of egg yolk IgY on carboxylated polypyrrole films for impedimetric detection of PfHRP2 antigen
2022 - GANDARILLA, ARIAMNA M.D.; GLORIA, JULIANE C.; BARCELAY, YONNY R.; SOUZA, RODRIGO F.B. de; MARIUBA, LUIS A.M.; BRITO, WALTER R.
This paper described an impedimetric immunosensor for detecting Plasmodium falciparum histidine-rich protein 2 (PfHRP2). Antibodies from egg yolk (Ab-PfHRP2, IgY type) were linked covalently to the screen-printed gold electrodes (SPGE) surface modified with a thin film of Poly-pyrrole-pyrrole 3 carboxylic acid (P(Py-Py3COOH) to develop the sensing platform. The fabrication steps were followed by microscopic (scanning electron microscopy), spectroscopic (RAMAN spectroscopy and Energy-dispersive X-ray spectroscopy), and electrochemical (electrochemical impedance spectroscopy (EIS) and cyclic voltammetry) techniques. The determination of Ag-PfHRP2 was performed by EIS, and the BSA(bovine serum albumin)/Ab-PfHRP2(IgY)/P(Py-Py3COOH)/SPGE immunosensor recorded a linear response at 100–1000 ng mL−1 concentration range, with a limit of detection (LOD) of 27.47 ng mL−1. Its performance was confirmed by Enzyme-Linked Immuno-Sorbent Assay. The fabricated device uses a simple strategy of IgY immobilization, showing high sensitivity and good selectivity, and can be considered an alternative for carrying out malaria tests.
Layered graphene/hexagonal boron nitride nanosheets (Gr/h-BNNs) applied to the CO2 photoconversion into methanol
2022 - GOMES, PAULO V.R.; AZEREDO, NATHALIA F.B.; GARCIA, LUIS M.S.; ZAMBIAZI, PRISCILLA J.; MORSELLI, GIOVANNI R.; ANDO, ROMULO A.; OTUBO, LARISSA; LAZAR, DOLORES R.R.; SOUZA, RODRIGO F.B. de; RODRIGUES, DEBORA F.; NETO, ALMIR O.
Photocatalysts based on heterostructure 2D materials show promising properties for the construction of optoelectronic devices for selective reduction of CO2 to methanol. In this sense, a fast and simple method to produce 2D hexagonal hybrid BN nanosheets (h-BNNs) doped with graphene heterostructure by van der Waals interactions was developed. The method used plasma created by a Tesla coil. The Gr/h-BNNs hybrid material obtained presented a stacking structure containing h-BNNs and graphene layers. The structure included doping of carbon atoms along the h-BN edge structures. The doping of the h-BN nanostructure with graphene sheets, conferred adaptable optical properties to the semiconductor, resulting in band gap energy values favorable to photocatalysis. The reaction promoted selective reduction of CO2 to methanol, and synthesis of other products, such as formaldehyde and formic acid, due to multielectronic transfer processes.
New approach by electrospray technique to prepare a gas diffusion layer for the proton exchange membrane fuel cell anode
2021 - SILVA, L.M.G.; LEOCADIO, G.N.; SOUZA, R.F.B. de; MIERZWA, J.C.; DUONG, A.; VENANCIO, E.C.; NETO, A.O.
The performance of the electrospray technique was applied to obtain a gas diffusion layer (GDL) for a proton exchange membrane fuel cell. It was confirmed by confocal microscopy that polytetrafluorethylene (PTFE) was impregnated into the backbone, forming a dispersed layer of microscopic size homogeneously distributed over the substrate. The PTFE layer was characterized by infrared spectroscopy and thermogravimetric analysis. In this work, we demonstrated that the use of the GDL prepared by electrospray increases the maximum power of the H2/O2 fuel cell by about 10% and decreases the diffusion loss of the electrode owing to a better distribution characteristic hydrophobic coating with low impedance to gas diffusion. Thus, our method is promising for the development of fuel cells by the production of diffusion layers.
Facile, clean and rapid exfoliation of boron-nitride using a non-thermal plasma process
2021 - SOUZA, RODRIGO F.B. de; MAIA, VICTORIA A.; ZAMBIAZZI, PRISCILLA J.; OTUBO, LARISSA; LAZAR, DOLORES R.R.; NETO, ALMIR O.
Non-Thermal Plasma source was used in this work to exfoliated boron-nitride (BN) powders. The generation of hexagonal BN nanosheets (h-BNNSs) few-layered was observed by TEM. The hBN exfoliation occurred along their transverse axis, preserving the hexagonal structure. The micrographs showed ordered lattice fringes with d-spacing of approximately 0.33 nm indicating the increase of (0 0 2) h-BNNSs crystal lattice planes, also confirmed by the relative peak intensity decrease in relation to the other peaks in XRD measures. The few amounts of layers were confirmed by intensity decrease, enlargement, and blue shift of E2 g vibrational mode in Raman spectra. Moreover, the appearance of the FTIR band corresponding to the hydroxyl group occurs due to large amounts of defects such as vacancy defects.
Glycerol dehydrogenation steps on Au/C surface in alkaline medium
2021 - FONTES, E.H.; RAMOS, C.E.D.; OTTONI, C.A.; SOUZA, R.F.B. de; ANTOLINI, E.; NETO, A.O.
The glycerol oxidation reaction (GLYOR) was evaluated using an Au/C electrocatalyst under alkaline conditions and varying glycerol (GLY) concentration. This electrocatalyst was synthesized by the borohydride reduction method. Au/C was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and electrochemical techniques associated with in situ attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR). XRD diffractograms showed the presence of Au (fcc). Cyclic voltammetry assisted by ATR-FTIR in situ measurements revealed that GLY oxidation on gold leads to the formation of a high amount of glyceraldehyde (GLYAD) for low GLY concentrations, while a lower amount of GLYAD was observed and the formation of dihydroxyacetone (DHA) was prevalent for high GLY concentrations. For high GLY concentrations DHA is almost stable, whereas for low GLY concentration DHA is fast oxidized to hydroxypyruvate. The excellent GLYOR activity of the Au/C catalyst in low GLY concentrations leads to the formation of deeper oxidized C1 species.
Effect of Ni content in PdNi/C anode catalysts on power and methanol co-generation in alkaline direct methane fuel cell type
2020 - SANTOS, M.C.L.; GODOI, C.M.; KANG, H.S.; SOUZA, R.F.B. de; RAMOS, A.S.; ANTOLINI, E.; NETO, A.O.
PdNi electrocatalysts supported on carbon were used as anode materials for methane oxidation in alkaline direct methane fuel cells (ADMEFCs). The electrocatalysts were successfully synthesized by the NaBH4 reduction method. X-ray diffraction measurements showed the formation of non-alloyed Pd in the face- centered cubic (FCC) structure for all materials and formation of NiO and Ni(OH)2 species. TEM images showed that the metal particles are well dispersed on the support with small agglomeration regions. Information about the surface structure of the catalyst were obtained by Raman spectra, mainly confirming the presence of Ni(OH)2. The species observed by DEMS, that is, methanol (m/z = 32), CO2 (m/ z = 44) and potassium formate (m/z = 84) were confirmed by FTIR, which also showed the presence of a high amount of carbonate in the methane oxidation products of the ADMEFC with Pd50Ni50/C as the anode catalyst. Tests in ADMEFCs showed that the dependence of the maximum power density on nickel content in the catalysts goes through a maximum value of 13.5 lW cm 2 at 50 at% Ni. Moreover, the amount of produced methanol decreases with increasing Ni content in the PdNi/C catalysts. Both these results can be explained by the enhanced methanol oxidation in the presence of nickel.