Surface analysis of Ti/Sb-SnO₂/PbO₂ electrode after long time electrolysis

The surface morphology is significant on the stability of electrode. In this study, the surface morphology of a target electrode, Ti/Sb-SnO₂/PbO₂, was analyzed after long time electrolysis under constant current density conditions in Na₂SO₄ solution. SEM, EDS, XRD and ICP-OES were used to characterize the change of its surface morphology and the metal content in the electrolyte solution. The SEM images show that the dissolution and detachment phenomenon occur on the surface of Ti/Sb-SnO₂/PbO₂ electrode after long time electrolysis. Pb element is detected in the electrolytes after electrolysis, which uncovers the dissolution of PbO₂. The XRD patterns indicate that the surface layer is still PbO₂ but the intensity of diffraction peaks is decreased. It is speculated that the mechanisms of the Ti/Sb-SnO₂/PbO₂ electrode deactivation are the oxide layer dissolution, detachment and the substrate passivation.