Catalysis, Chemical Engineering, General Chemical Engineering, Energy Engineering and Power Technology
51
Scopus Publications
Scopus Publications
Unveiling the photocatalytic potential of Co-doped BaBiO3 through facile sol-gel synthesis and comprehensive characterization N.F. Andrade Neto, T.B.F. Gurgel, V.R. Mastelaro, M.R.D. Bomio, F.V. Motta Inorganic Chemistry Communications, 2026 In this study, powders of BaBi (1- x ) Co x O 3 (with x = 0, 1, 2, 4, and 8 mol%) were synthesized using a sol-gel method. These samples were characterized by several techniques, including X-ray diffraction (XRD), Raman scattering, UV–Visible spectroscopy, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS, Mott-Schottky), and field-emission scanning electron microscopy (FESEM) with associated EDX chemical analysis. The photocatalytic properties were then assessed against methylene blue (MB) dye. The results indicate that Co doping preferentially occurs at the Bi 3+ sites, leading to the formation of defects in the BaBiO 3 lattice. These defects significantly enhance the photocatalytic activity, leading to approximately 80% MB degradation within 120 min. The photocatalytic activity of BBO against MB dye showed a 14% increase in efficiency under acidic pH conditions, whereas the BBO8C sample proved to be 22% more efficient in a neutral medium compared to the acidic environment. The photocatalytic process was primarily driven by electron-mediated phenomena, as indicated by the 8% and 71% reductions in activity for BBO and BBO8C, respectively, upon the addition of electron scavengers. The findings suggest that Co-doped BaBiO 3 is a promising material for liquid waste treatment, demonstrating effectiveness in degrading methylene blue dye under various environmental conditions. • Facile sol-gel synthesis of Co-doped BaBiO 3 without secondary phases. • Co doping shifts the CB from −0.26 to −0.77 V for enhanced photoactivity. • BaBiO 3 :8%Co achieved 80% degradation of MB dye within 120 min. • The photocatalytic process is primarily driven by electrons. • High chemical stability and reusability over four consecutive catalytic cycles.
A Facile Microwave-Assisted Hydrothermal (MAH) Method of CdWO4/CdMoO4 Heterostructures and Their Photocatalytic Properties Nivaldo F. Andrade Neto, Onecima B. M. Ramalho, Marcio D. Teodoro, Mauricio R. D. Bomio, Fabiana V. Motta Ceramics, 2025 In this study, CdWO4/CdMoO4 powders’ heterostructures were synthesized using the microwave-assisted hydrothermal method, characterized, and evaluated for their photocatalytic properties. The samples were analyzed using X-ray diffraction (XRD), Raman and ultraviolet-visible (UV-Vis) spectroscopy, field-emission scanning electron microscopy (FESEM), and photoluminescence (PL). The photocatalytic performance was assessed using methylene blue as a model pollutant. XRD patterns and Raman spectra confirmed the formation of heterostructures containing the Wolframite phase of CdWO4 and the Scheelite phase of CdMoO4. FESEM micrographs revealed that the CdWO4 phase exhibits a plate-like morphology, while the CdMoO4 phase consists of irregular nanoparticles. Photocatalytic tests demonstrated that the 20Mo sample exhibited the best performance, degrading 96% of the dye after 2 h of reaction. The findings of this study indicate that CdWO4/CdMoO4 heterostructures hold significant potential for photocatalytic applications in the degradation of cationic dyes.
Photoluminescent and photocatalytic properties of Cu2+ and Mg2+-doped ZnO nanoparticles obtained by a facile sonochemical method I. A. Bezerra Neta, N. F. Andrade Neto, J. M. P. Silva, M. D. Teodoro, M. R. D. Bomio, F. V. Motta International Journal of Ceramic Engineering and Science, 2023 Pure ZnO particles, doped and co‐doped with Cu2+ and Mg2+ ions, were obtained by the simple sonochemical method. The wurtzite hexagonal structure was confirmed by X‐ray diffraction (XRD) patterns. The images obtained by field emission scanning electron microscopy (FE‐SEM) showed irregular and more agglomerated particles with the increase of Cu2+ and Mg2+ ions concentration in the ZnO lattice, with the average diameter of particles in the range of 57.23–170.77 nm. The photocatalytic activity was investigated by decolorizing the methylene blue (MB) dye under ultraviolet C (UVC) light irradiation which indicates that 1% Mg‐doped ZnO particles have better the photocatalytic activity than the other samples, and presented the highest kinetic constant value. The co‐doped samples showed a reduced global surface area which did not favor the good photocatalytic performance. The sacrificial agents showed that OH• radicals are the main species involved in the photocatalytic activity of this system and defects generated in the ZnO lattice promoted photoluminescent emission in the red and green regions.
Effect of the Cross-Section Morphology in the Antimicrobial Properties of α-Ag2WO4 Rods: An Experimental and Theoretical Study Nivaldo F. Andrade Neto, Marisa C. Oliveira, José Heriberto O. Nascimento, Elson Longo, Renan A. P. Ribeiro, Mauricio R. D. Bomio, Fabiana V. Motta Applied Nano, 2023 In this work, α-Ag2WO4 particles with different cross-sections were obtained using the co-precipitation method at different synthesis temperatures. The samples were characterized by X-ray diffraction (XRD), field-scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity was analyzed using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) methods against the Escherichia coli and Salmonella spp. gram-negative bacteria. The antimicrobial tests against Escherichia coli and Salmonella spp. indicated that concentrations of 2.5–5 mg/mL and 5 mg/mL completely inhibit its growth, respectively. The antimicrobial activity was analyzed employing band-edge positions for ROS generations and the superficial distribution of Ag+ species that contribute to antimicrobial activity. Quantum-chemical calculations were used at the DFT level to investigate the surface-dependent reactivity of α-Ag2WO4, and we demonstrated how the antimicrobial properties could be tailored by the geometry and electronic structure of the exposed surfaces, providing guidelines for the morphology design.
