Photo- and electro-oxidation of tetracycline hydrochloride on self-doped titanium dioxide nanotubes modified by Pt sub-monolayers

Autor(es)

Gomes Bezerra, Carlos Andre ; Tenorio da Silva Santos, Joao Paulo ; Bessegato, Guilherme Garcia ; de Paiva E Silva Zanta, Carmem Lucia ; Del Colle, Vinicius ; Tremiliosi-Filho, Germano

• Tipo de documento: Artigo Científico
• Fonte: Electrochimica Acta; v. 404, p. 9-pg., 2022-02-01.

Resumo

This work presents a methodology for obtaining self-doped titanium dioxide nanotubes (SD-TNT) and self-doped titanium dioxide nanotubes modified with Pt electrodeposition (SD-TNT/Pt) for electro-oxidation (EO) and photo-electro-oxidation (PEO) of Tetracycline Hydrochloride (TCH). The SD-TNT electrode was obtained by anodization of titanium foil and the Pt electrodeposition was performed by pulsed potentiometry. Uniform nanotubes distribution with diameters of similar to 100 nm, wall thickness of similar to 16 nm, and length of similar to 11.2 mu m in the anatase phase of TiO2 were obtained. Electron Paramagnetic Resonance (EPR) analysis suggest both electrodes, TNT and SD-TNT, presented a paramagnetic signal and SD-TNT showed a higher signal intensity which indicates reduction of Ti4+ species to Ti3+ during the self-doping treatment. Energy Dispersive X-ray Spectroscopy (EDS) confirmed the presence of 0.56% of Pt mass on SD-TNT/Pt. Cyclic voltammetry (CV) results also confirmed the presence of Pt. The SD-TNT showed a similar to 5 order of magnitude higher value of the density of charge carriers (ND = 2.2 x 10(20) cm(-3)) than the no doped one (2.9 x 10(15) cm(-3)). In 180 min of EO and PEO, for both electrodes, there was 100% of TCH degradation and presented in all cases a first-order kinetic model. PEO using platinum-decorated (SD-TNT/Pt) electrodes showed poorer performance due to the light-blocking effect of Pt nanoparticles and the potential trapping of electrons. PEO of TCH with SD-TNT reached the best mineralization of pollutant, 94.2% of Total Organic Carbon (TOC) abatement, an Energetic Consumption per unit TOC removed (ECTOC) of 0.265 kWh (g TOCremoved)(-1) and a Mineralization Current Efficiency (MCE%) of 15.2%. Thus, SD-TNT electrodes could be effectively used as an alternative to high-cost anodes such as BDD both in electro-oxidation and photo-electro-oxidation of organic contaminants. (c) 2021 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 17/01189-0 - Novel aging: tecnologias e soluções para fabricar novos produtos lácteos para um envelhecimento saudável
• Beneficiário: Daniel Rodrigues Cardoso
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 19/22183-6 - Electrocatálise VI: aspectos fundamentais e aplicados em problemas emergentes e clássicos em conversão eletroquímica de energia
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Temático