Electrochemistry and Electroanalytical chemistry play an important role to face the challenges of the contemporary world. They have contributed to the advance of the scientific development of our country, helped to promote economic and social progress as well as cultural dissemination. These areas have greatly contributed to the knowledge about thermodynamics and kinetics of the electron transfer reactions, energy conversion, synthesis and modification of compounds, corrosion, and development of fast, sensitive, and selective analytical methods. This work presents an overview of the areas by analyzing the technical and scientific papers produced in Brazil on these subjects, and the analysis of the Brazilian scientific societies that were formed and consolidated, which have contributed to spread the scientific knowledge. The improvement of these areas can be attributed to the good quality of the human resources formed during long time as well as the growing of distribution of research groups in different regions of the country. The success/future of these areas are associated with good academic/scientific education, low cost of instrumentation, formation of networks of excellence between researchers, and large cooperation projects that improved with the sharing of ideas, technologies, infrastructure, and equipment. All of which has contributed to strengthening consolidated and emerging graduation programs.

The electrochemical reduction of the disperse azo dyes Red1, Red13 and Orange1 (Or1) was investigated in the RTILs [C4mim][NTf2] and [C4mpyrr][NTf2], and in contrast with their behavior in conventional aprotic solvents, was shown to proceed via a reversible one electron step to form stable radical anion, which is further reduced at more negative potentials to the dianion. In [C4mpyrr][NTf2], cleavage of the N-H bond on the secondary amine was inferred for Orange1, and the ease at which this cleavage occurred is rationalized in terms of acidity of the amine moiety. The ease of reduction was observed to decrease in the order Or1 > Red13 > Red1, and is related to the electron delocalization within the molecule and the electron withdrawing power of the substituents. The dyes were then oxidized, and Red1 and Red13, bearing an aliphatic amine, were oxidized in a reversible one electron step, to generate the radical cations. The presence of a primary aromatic amine in Or1 provokes a positive shift in the potential of the oxidation peak and shows reversible voltammetry only at scan rates above 200 mV s-1. The ease of oxidation decreases in the order Red1 > Red13 > Or1, and is thought to relate to the detected mutagenic activity of the dyes. © 2009 by ESG.

O objeto da presente patente é um reator fotoeletrocatalítico operando com eletrodos nanoporosos ou nanotubulares de Ti/TiO~ 2~ como fotoanodos, uma rede de platina como cátodo para oxidação fotoeletrocatalítica de efluentes coloridos, sob densidade de corrente constante e irradiação de luz UV, utilizado no tratamento de águas de rejeito contendo corantes ácidos, básicos, dispersos, reativos e agentes dispersantes e efluentes coletados de indústrias têxteis. Ambos os eletrodos mostraram uma performance acima dos métodos usuais removendo não apenas a coloração, mas processando grande mineralização dos diversos tipos de corantes, surfactantes etc. em efluentes da industria têxtil.