Justyna Czupryniak

Application of BDD thin film electrode for electrochemical decomposition of heterogeneous aromatic compounds

The aim of the presented study is to investigate the applicability of electrochemical oxidation of aromatic compounds containing heteroatoms, e.g. waste from production of pesticides or pharmaceutics, at a borondoped diamond (BDD) electrode. The BDD electrodes were synthesized by microwave plasma enhanced chemical vapour deposition (MW PE CVD). Investigation of the electrode surface by optical microscopy and scanning electron microscopy (SEM) confirmed that the synthesized layer was continuous and formed a densely packed grain structure with an average roughness of less than 0:5 μm. The influence of important electrochemical parameters: current density, kind of reactor, pH or mixing operation, on the efficiency of the oxidation was investigated. The fouling of electrode’s surface caused by the deposition of organic material was observed during CV and galvanostatic experiments. At low current density the oxidation rate constant k was low, but the current efficiency was relatively high. The BDD can be used successfully to remove heterogeneous aromatic compounds existing either as molecules or cations. During 4 h of electrolysis 95% of aromatic compounds were electrochemically decomposed to mineral forms. It was observed that the influence of the initial pH on mineralization was marginal.

The electrochemical and spectroscopic characterization of 1,4 and 1,8-aminoanthraquinone derivatives

The acid base properties of 1,4 and 1,8-anthraquinone derivatives were determined in methanol and acetonitrile by pH-spectroscopic measurements. The examined compounds was also characterized by electrochemically using cyclic voltammetry in DMSO solutions.

Influence of substituent on spectroscopic and acid-base properties of anthraquinone derivatives

A series of 1,4-disubstituted aminoanthraquinones has been prepared from 1,4 ditosyloksyanthraquinone. The potentiometric and UV-spectrophotometric method have been used to study the acid-base properties of obtained compounds. The absorption spectra revealed the presence of vibroelectronic band in visible region for compounds containing two tertiary nitrogen groups. It indicates the separation of vibronic states in the molecule. Determined pKa values in acetonitrile used as a solvent indicate the influence of substitution of amino group on basicity of the anthraquinone moiety.