Electrochemical stability and corrosion mechanism of fluorine-doped tin oxide film under cathodic polarization in near neutral electrolyte

• Main Authors: Sanz-Navarro, Carlos Federico, Lee, Siaw Foon, Yap, Seong Shan, Nee, Chen Hon, Yap, Seong Ling
• Format: Article
• Published: Elsevier Science SA 2023
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/38776/

Commercial fluorine-doped tin oxide (FTO) coated glass slides were subjected to different cathodic potentials for 15 min in 0.2 M Na2SO4 of pH 6.42 to study their electrochemical stability. Results showed that FTO could maintain its electrochemical stability until-1200 mV. However, when it was cathodically polarized from-1600 mV to more negative potentials, band structure positions started to shift upwards, the electrolyte became more acidic and a porous structure appeared on the FTO surface. At-2000 mV, a layer of metallic Sn was seen deposited on the FTO surface, verified by X-ray diffraction and scanning electron microscopy - energy dispersive X-ray spectroscopy. During the cathodic corrosion in near neutral electrolyte, the reduction of SnO2 to Sn in-volves water oxidation as well as hydrogen evolution reaction.