▎ 摘　　要

A Pb2+ ion-selective membrane electrode (ISME) based on graphene Th(IV) phosphate composite cation-exchange material was fabricated using solution casting method. The effect of membrane composition on the proton conductivity was investigated using varying amounts of electroactive material. The membrane with 250mg of electroactive material and 10L of plasticizer exhibited highest proton conductivity. The optimized membrane composition was used for the fabrication of ISME which exhibited a typical Nernstian response towards Pb2+ ions in the concentration range 1.0x10(-1) to 1.0x10(-7)M with a sub-Nernstian slope of 27.65mV per decade change in Pb2+ ion concentration. The response time of this electrode for Pb2+ ions was found to be 10s and the electrode can be used for 120d without any considerable divergence in response potential and can be used in the pH range from 3.0 to 7.0. It was found selective for Pb2+ ions in the presence of various monovalent and multivalent interfering ions. It was also employed as an indicator electrode in the potentiometric titration of Pb2+ ions using ethylenediamine tetraacetic acid, disodium salt as titrant.