Ref.: MmeCa32-002
Apresentador: Lucas Sevieri Chagas
Autores (Instituição): Chagas, L.S.(Universidade Federal do ABC); Antunes, R.A.(Universidade Federal do ABC); Nishihora, R.K.(Universidade Federal do ABC); Albertin, K.F.(Universidade Federal do ABC); Mendes Filho, A.A.(Universidade Federal do ABC);
Resumo:
Ttitanium dioxide nanotubes (TiO2), referred to as TNTs, are fabricated on titanium alloy substrates via electrochemical anodization, presenting promising prospects for pollutant degradation through photodegradation mechanisms. These structures possess semiconductor characteristics with a narrow band gap and extensive surface area, facilitating interactions with organic molecules upon exposure to light. While prior investigations predominantly focus on commercially pure titanium as the substrate, this study scrutinizes the growth and compositional properties of TNTs grown on a Ti-29Nb-13Ta-4.6Zr alloy (TNTZ), particularly emphasizing their potential in pollutant degradation applications. Following anodization synthesis, SEM analysis unveils well-ordered nanotube formations devoid of residual ribs, optimizing electron-hole contact for enhanced photocatalytic efficiency. XPS spectra deconvolution indicates variable oxide compositions, correlating with film depth and potentially originating from defects within the crystal lattice induced by oxide formation, thereby influencing nanotube properties. Additionally, XPS depth profiling reveals a predominance of high oxidation states on the tube surface, suggesting the formation of diverse morphologies associated with defects in the oxide lattice, yielding metastable oxides. Upon annealing, the TNTs adopt anatase crystal structure, known for its superior photocatalytic properties. Assessment of photocatalytic activity using methylene blue (MB) degradation demonstrates heightened efficiency with higher nanotube structures, underscoring the significance of nanotube morphology and composition in enhancing photocatalytic performance.