Towards a higher photostability of ZnO photo-electrocatalysts in the degradation of organics by using MMO substrates

Autor(es)

Goulart, Lorena A. ^{[1, 2]} ; Santos, Gessica O. S. ^{[2, 3]} ; Eguiluz, Katlin I. B. ^{[3, 4]} ; Salazar-Banda, Giancarlo R. ^{[3, 4]} ; Lanza, V, Marcos R. ; Saez, Cristina ^[2] ; Rodrigo, Manuel A. ^[2]

Afiliação do(s) autor(es)

^[1] V, Univ Sao Paulo, Inst Chem Sao Carlos, POB 780, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Castilla La Mancha, Dept Chem Engn, Campus Univ S-N, Ciudad Real 13071 - Spain

^[3] Univ Tiradentes, Proc Engn Postgrad PEP, BR-49037580 Aracaju, SE - Brazil

^[4] Res & Technol Inst ITP, Electrochem & Nanotechnol Lab, Aracaju, SE - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Chemosphere; v. 271, MAY 2021.
• Citações Web of Science: 0

Resumo

In this work, it is proposed a novel strategy to increase the photostability of the ZnO photoelectrocatalyst under prolonged light irradiation, without the addition or deposition of metals and/or semiconductor oxides during their synthesis. This strategy is based on the use of a mixed metal oxide (MMO-Ru0.3Ti0.7O2) coating as the substrate for the electrodeposition of ZnO. To assess it, the electrodeposition of ZnO films on Ti and Ti/MMO substrates and the photoelectrocatalytic activity of these materials for the degradation of the herbicide clopyralid were studied. The results showed that the substrate directly influenced the photo-stability of the ZnO film. Under the incidence of UV light and polarization, the novel Ti/MMO/ZnO electrode showed greater photocurrent stability as compared to Ti/ZnO, which is a very important outcome because the behavior of these electrodes was similar when compared in terms of the degradation of clopyralid. Single electrolysis was not able to degrade efficiently clopyralid at the different potentials studied. However, the irradiation of UV light on the polarized surface of the Ti/ZnO and Ti/MMO/ZnO electrodes increased markedly the degradation rate of clopyralid. A synergistic effect was observed between light and electrode polarization, since the rate of degradation of clopyralid was twice as high in photoelectrocatalysis (PhEC) than in photocatalysis (PhC) and different intermediates were formed. From these results, mechanisms of degradation of clopyralid for the PhC and PhEC systems with the Ti/ZnO and Ti/MMO/ZnO electrodes were presented. Therefore, the Ti/MMO/ZnO electrode could be a cheap and simple alternative to be applied in the efficient photodegradation of organic pollutants, presenting the great advantage of having a facile synthesis and high capacity to work at relatively low potentials. (C) 2020 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 16/08760-2 - Heterojunções de NiO/ZnO e CuO/ZnO aplicadas na degradação fotoeletrocatalítica de trimetoprim e levofloxacina
• Beneficiário: Lorena Athie Goulart
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/04084-0 - Eletrodos de heterojunção de óxidos aplicados na fotoeletrocatálise de antibióticos em reatores de fluxo
• Beneficiário: Lorena Athie Goulart
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 14/50945-4 - INCT 2014: Instituto Nacional de Tecnologias Alternativas para Detecção, Avaliação Toxicológica e Remoção de Micropoluentes e Radioativos
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/10118-0 - Estudo e aplicação da tecnologia eletroquímica para a análise e a degradação de interferentes endócrinos: materiais, sensores, processos e divulgação científica
• Beneficiário: Marcos Roberto de Vasconcelos Lanza
• Modalidade de apoio: Auxílio à Pesquisa - Temático