Photoelectrochemical or electrophotochemical processes?

• Autor(a) principal: Peralta-Zamora,Patricio
• Data de Publicação: 2010
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532010000900004
• topic: photoelectrochemical; degradation; synergetic effect

In recent years, many studies have related the efficient degradation of relevant substrates by photoelectrochemical processes. Usually, it is accepted that the synergy observed between photo and electrochemical processes involves the improvement of the photocatalytic efficiency as a result of a favorable electrochemical support. In this work some experimental observations are discussed with the aim of demonstrating that in several situations, the synergic effect involves a divergent concept. That is, an efficient electrochemical-based process assisted by subsequent photochemical reactions. As far as we know, the high degradation capacity shown by DSA electrodes used in the presence of reactive electrolytes, such us sodium chloride, is due to electrochemical generation of powerful oxidant agents, as molecular chlorine, followed by photochemical generation of active radicals, such chlorine radical. This assumption becomes clearly visible in degradation studies involving humic acid, camphor and an anthraquinone dye (reactive blue 19).