SODIUM-ION SENSITIVE ELECTRODE BASED ON A MOLYBDENUM OXIDE BRONZE

New sodium ion sensitive metal-oxide-type sensors have been developed and tested with a direct solid state contact method. Performance was d emonstrated at ambient temperature with single crystals of Na0.9Mo6O17 and Li0.33MoO3. The sodium molybdenum bronze sensor responded reprodu cibly and fast to changes of Na+ concentration in the range of 1-10(-4 ) mol dm(-3). Cross sensitivity tests to other ions such as H+ or K+ h ave shown that the new sodium ion sensor may be used when the concentr ation of other ions is an order of magnitude smaller than the Na+ conc entration.