Preparação, caracterização e aplicação de eletrodos bicomponentes de 'W' / 'WO IND. 3' / 'TIO IND 2' na oxidação fotoeletrocatalítica e fotocatalítica de corantes de cabelos
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Data
2012-05-25
Autores
Fraga, Luciano Evangelista [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Nos anos mais recentes, o uso indiscriminado de corantes para tintura de cabelo tem despertado grande atenção em virtude de alguns aspectos toxicológicos e mutagênicos. Os efluentes provenientes de salões de beleza e esgotos domésticos quando não convenientemente tratados podem atingir estações de tratamento de água e mananciais, levantando preocupações com a saúde humana e proteção ambiental. O presente trabalho explora novos materiais a serem utilizados em tratamentos de efluentes contaminados por corantes de cabelo por técnicas fotocatalítica e fotoeletrocatalítica. Dentro deste contexto, investigou-se a síntese do eletrodo de Ti/TiO2 através do método sol-gel, e dos eletrodos de W/WO3 e W/WO3/TiO2, utilizando-se métodos eletroquímicos, visando ampliar a faixa de utilização destes eletrodos para a fotoexcitação na região do visível. Estes eletrodos foram caracterizados e aplicados na oxidação fotoeletrocatalítica e fotocatalítica dos corantes básicos de cabelo vermelho básico 51(VB51), marrom básico 16(MB16) e azul básico 99(AB99) presentes em formulações comerciais de tintura temporária e semi permanente. Para isto testou-se os processos sob irradiação nas regiões do ultravioleta e visível visando melhorar a eficiência destes processos e aproveitamento da luz solar. Utilizando-se concentração de 3,33x10-5 mol L-1 do corante em Na2SO4 0,10 mol L-1 pH= 2,0 sob densidade de corrente [ I ]= 1,25 mA cm-2 observa-se 100% de descoloração e 88% de remoção de COT para tratamento por oxidação fotoeletrocatalítica do corante VB51, sob radiação visível. No fotoanodo de W/WO3 observou-se 100% de remoção da cor e 83% de remoção de COT. O método foi testado para os corantes de cabelo MB16 e AB99 e, observou-se 100% de descoloração com 55% e 43% de remoção de...
In recent years, the indiscriminate use of dyes for hair dye has attracted great attention due to some toxicological and mutagenic aspects. As a result the effluent from beauty salons and domestic sewages when not properly treated can reach water treatment plants and water sources, raising concerns about human health and environmental protection. This work explores new materials to be used in the treatment of effluents contaminated with dyes hair for photocatalytic and photoelectrocatalytic techniques. Within this context, we investigated the synthesis of the Ti/TiO2 electrode through the sol-gel method, and the W/WO3 and W/WO3/TiO2 electrodes, using electrochemical methods in order to extend the range of use of these electrodes for photoexcitation in the visible region. These electrodes were characterized and applied in the photoeletrocatalytic and photocatalytic oxidation of basic hair dyes Basic Red 51(VB51), Basic Brown 16(MB16) and Basic Blue 99(AB99) present in commercial formulations of temporary and semipermanent dyeing. For this purpose, the processes were tested under irradiation in ultraviolet and visible regions, aiming to improve their efficiency to use on sunlight. Using 3.33 × 10 -5 mol L-1 dye solution in 0.10 mol L-1 Na2SO4 pH = 2.0 under current density [I] = 1.25 mA cm-2 shows 100% bleaching and 88% TOC removal for treatment by photoeletrocatalytic oxidation of the VB51 dye under visible irradiation. In W/WO3 photoanode showed 100% color removal and 83% TOC removal. The method was also tested for hair MB16 and AB99 dye, exhibiting 100% of discoloration with 55.37% and 43.11% TOC removal for W/WO3/TiO2 photoanode, and 100% and 75% of discoloration with 49% and 34% TOC removal for AB99 and MB16 dyes, respectively. The materials efficiency was also evaluated under UV irradiation and 100% of discoloration was obtained for the W/WO3/TiO2 photoanode... (Complete abstract click electronic a
In recent years, the indiscriminate use of dyes for hair dye has attracted great attention due to some toxicological and mutagenic aspects. As a result the effluent from beauty salons and domestic sewages when not properly treated can reach water treatment plants and water sources, raising concerns about human health and environmental protection. This work explores new materials to be used in the treatment of effluents contaminated with dyes hair for photocatalytic and photoelectrocatalytic techniques. Within this context, we investigated the synthesis of the Ti/TiO2 electrode through the sol-gel method, and the W/WO3 and W/WO3/TiO2 electrodes, using electrochemical methods in order to extend the range of use of these electrodes for photoexcitation in the visible region. These electrodes were characterized and applied in the photoeletrocatalytic and photocatalytic oxidation of basic hair dyes Basic Red 51(VB51), Basic Brown 16(MB16) and Basic Blue 99(AB99) present in commercial formulations of temporary and semipermanent dyeing. For this purpose, the processes were tested under irradiation in ultraviolet and visible regions, aiming to improve their efficiency to use on sunlight. Using 3.33 × 10 -5 mol L-1 dye solution in 0.10 mol L-1 Na2SO4 pH = 2.0 under current density [I] = 1.25 mA cm-2 shows 100% bleaching and 88% TOC removal for treatment by photoeletrocatalytic oxidation of the VB51 dye under visible irradiation. In W/WO3 photoanode showed 100% color removal and 83% TOC removal. The method was also tested for hair MB16 and AB99 dye, exhibiting 100% of discoloration with 55.37% and 43.11% TOC removal for W/WO3/TiO2 photoanode, and 100% and 75% of discoloration with 49% and 34% TOC removal for AB99 and MB16 dyes, respectively. The materials efficiency was also evaluated under UV irradiation and 100% of discoloration was obtained for the W/WO3/TiO2 photoanode... (Complete abstract click electronic a
Descrição
Palavras-chave
Quimica analitica, Eletrodos, Corantes e tingimento, Electrodes
Como citar
FRAGA, Luciano Evangelista. Preparação, caracterização e aplicação de eletrodos bicomponentes de 'W' / 'WO IND. 3' / 'TIO IND 2' na oxidação fotoeletrocatalítica e fotocatalítica de corantes de cabelos. 2012. 157 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Química de Araraquara, 2012.