ZnS-Intercalated Montmorillonite: A Low Cost Potentiometric Sensor

Abstract

ZnS is well known for its potential uses, both in crystal form and powder, as optoelectronic devices and as a phosphor. In this work, we prepared ZnS-intercalated montmorillonite by the insitu solid-solid reaction between Zn (II)-montmorillonite and sodium sulfide. A potentiometric electrode was constructed from a mixture of ZnS-intercalated montmorillonite, artificial graphite, polytetrafluoroethylene (PTFE) and carboxymethylcellulose (CMC) in an appropriate ratio. The electrode was used to determine S2- in aqueous solution, graphs of log [S2-] vs. measured voltage gave linear relation up to 3rd order of ion concentrations. It can be said that, this is the first time that ZnS-intercalated montmorillonite is used to construct a potentiometric electrode. Apart from a good precision, the electrode is good for its selectivity, durability and low cost.