Electrochemical behaviour of CuxMo6S8 thin films synthesized by CSD

Cu2Mo6S8 thin films were synthesized on various substrates (R-sapphire, Mo, TiN/Si, Ti/Si and vitreous carbon) using chemical solution deposition from intermediate oxides obtained by the polymeric precursor method. The structural and microstructural characteristics of the films were studied by X-ray diffraction and field emission scanning electron microscopy. The electrochemical intercalation/de-intercalation was evaluated on these films by cyclic voltammetry and differential pulse voltammetry in aqueous CdSO4 10−1, 10−5 and 10−6 M solutions. This work demonstrated the intercalation capacity of the Cu2Mo6S8 films and the best results were obtained on TiN/Si: fast and reversible intercalation process, with cyclability higher than 100 cycles for an aqueous CdSO4 10−1M solution which demonstrates the possibility to re-use the Cu2Mo6S8 electrode. At lower concentration, differential pulse voltammetry method allowed to detect Cd2+ with a minimal sensitivity of the order of 10−6M. These results offer promising perspectives for intercalation/de-intercalation of other heavy metal ions at low concentrations in Cu2Mo6S8 films on TiN/Si and thus for future applications such as miniaturized electrochemical sensors.