Synthetic Boron-Doped Diamond Electrodes for Electrochemical Water Treatment

Boron-doped diamond electrodes have emerged as anodic material due to their high physical, chemical and electrochemical stability. These characteristics make it particularly interesting for electrochemical wastewater treatments and especially due to its high overpotential for the Oxygen Evolution Reaction. Diamond electrodes present the maximum efficiency in pollutant removal in water, just limited by diffusion-controlled electrochemical kinetics. Results are presented for the elimination of benzoic acid and for the electrochemical treatment of synthetic tannery wastewater. The results indicate that diamond electrodes exhibit the best performance for the removal of total phenols, COD, TOC, and colour.

Novel silica membrane material for molecular sieve applications

Development of new silica membranes properties, e.g., molecular sieving properties, has been increasingly gaining importance in the last few years. A novel unsupported silica membrane, referred to as hydrophobic metal-doped silica, was developed by cobalt-doping within the organic templated silica matrix. The novel material was prepared by the acid-catalyzed hydrolysis and condensation process of tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES), which is the precursor for methyl ligand covalently bounded to the silica matrix. The synthesis and surface properties of the novel unsupported silica membrane as well as the unsupported blank silica and modified silica membranes were revealed by surface and microstructural techniques, such as water contact angle measurement, FTIR, X-ray, Solid-state 29Si MAS NMR, TGA and N2 and CO2 adsorption measurements. The results showed that the thermal stability of the organic templated silica matrix was enhanced by cobalt-doping process. A hydrophobic microporous silica membrane material with high thermal stability up to ∼560 °C in oxidizing atmosphere and a narrow pore size distribution centered at 1.1 nm was obtained. Therefore, a novel precursor material for molecular sieve silica membranes applications has been achieved and developed.