Nitrite Reduction Enhancement on Semiconducting Electrode Decorated with Copper(II) Aspirinate Complex

Autor(es)

Sayao, Fabiana A. ; da Silva Flor, Jader Barbosa ; Galvao Frem, Regina Celia ; Stulp, Simone ; Cardoso, Juliano C. ; Zanoni, Maria V. B.

• Tipo de documento: Artigo Científico
• Fonte: ELECTROCATALYSIS; v. 7, n. 6, p. 486-494, NOV 2016.
• Citações Web of Science: 0

Resumo

The present work seeks to describe a new approach characterized by copper(II) aspirinate complex deposited onto nanotube TiO2 electrodes as mediator of electron transfer during nitrite reduction, aiming at achieving a faster removal of nitrite to nitrogen species oxides. Thin films of copper aspirinate ({[}Cu-2(asp)(4)]) on the Ti/TiO2 nanotube surface are easily obtained following multi-scans (100 cycles) recorded for the Ti/TiO2 electrode in 0.1 mol L-1 NaCl, pH 4, containing 5.0 x 10(-4) mol L-1 of the copper coordination compound. The complex showed high adherence while the cyclic voltammograms presented redox peaks at -0.15/+0.15 V, which was attributed to the reduction of Cu(II) to Cu(I). Following 5 min of treatment using photoelectrocatalysis on Ti/TiO2-{[}(Cu)(2)Asp(4)] electrode, a total removal of nitrite was observed, which was found to be at least four times faster compared to Ti/TiO2 electrode. Concomitantly, we also observed a relatively good conversion to nitrogen-containing gaseous species (56 %) besides the formation of 42 % of ammonia. The results, in effect, also indicate that nitrate and nitrite are not detectable in the treated solution up to levels of 0.5 mg L-1. The method under consideration has successfully accounted for the maximum limit of nitrite recommended in drinking water which has been set to 1 mg L-1. (AU)

• Processo FAPESP: 15/18109-4 - Contribuição dos Materiais Nanoestruturados na Eletroanálise de Fármacos e Corantes, na Oxidação e Redução Fotoeletrocatalítica de Poluentes Orgânicos e Inorgânicos e Desinfecção de Água
• Beneficiário: Maria Valnice Boldrin
• Modalidade de apoio: Auxílio à Pesquisa - Regular