Physical adsorption of OH− causes anomalous charging at oxide–water interfaces

Abstract

This study reveals a charging mechanism at oxide–water interfaces, solving the puzzle that challenges the traditional electrical double layer (EDL) model. We found that the experimentally measured zeta potential is caused by physically adsorbed OH⁻, instead of acidic dissociation of surface OHs and the first-layer water. This mechanism should apply for a wide range of material interfaces and could find applications in future.