CdS-intercalated bentonite/carbon composite as electrode for sulfide ion

摘要

CdS, a bright yellow precipitate is well known for its optical, electrical, electro-optical and photochemical properties. CdS has also been prepared in the interlayer spaces of layered materials such as laponite and montmorillonite (bentonite). Several properties of intercalated CdS have been studied, but for the best of our knowledge there is no reports on its use. In this work, we applied CdS-intercalated bentonite / carbon composite as an electrode for determination of S~(2-) ion in aqueous solution. CdS- intercalated bentonite was prepared by the in situ solid-solid reaction between Cd(II)-bentonite and Na_2S. To construct a potentiometric electrode, CdS-intercalated bentonite was mixed with artificial graphite, polytetrafluoroethylene (PTFE) and carboxymethylcellulose (CMC) in an appropriate ratio. The electrode was used to determine S " in aqueous solution, graphs of log [S~(-2)] vs measured voltage (mv) gave linear relation up to 3 orders of ion concentrations. Apart from the reproducibility and good precision, the electrode is good for its selectivity, durability and low cost.