Voltammetric studies of the gradual thermal decomposition of activated carbon surface oxygen complexes

Eight samples of activated carbon with different quantities of chemically bound oxygen were obtained by heat treatment under vacuum (180–900 °C) of demineralised carbon previously oxidised with concentrated nitric acid. The surface chemistry of the modified materials was characterised by various techniques (elemental analysis, acid–base titration, XPS). For all carbon samples, cyclovoltammetric studies were carried out in phosphate buffers at different pH (1–13) using the powdered activated carbon electrode technique. The correlation between activated carbon surface chemistry and the electrochemical properties (potential response, double layer capacity) of powdered electrode is analysed and discussed.