Effects of inorganic substances on water splitting in ion-exchange membranes I.Electrochemical characteristics of ion-exchange membranes coated with iron hydroxide/oxide and silica sol

摘要

The effects of inorganic substances on water splitting in ion-exchange membranes(IEMs)were investigated.In this study,iron hydroxide/ oxide and silica sol were immobilized on the surface of the IEMs.The water-splitting capabilities of the metal-embedded cation-exchange membranes were 10~4-10~5 times greater than those of the virgin membranes at the same current density.Similarly,silica sol(i.e.,ident toSi-OH groups)deposited on the anion-exchange membrane surface also drastically increased the proton transport numbers.It was thought that the bipolar structure consisting of H- and OH-affinity groups immobilized on the IEM surface increased water-splitting due to the enhancement of water polarization with the help of strong electric fields.This study revealed that metal oxides or silica groups(ident toSi-OH),as well as metal hydroxides,can be used as catalysts for water splitting.