Indium Tin-Doped Oxide (ITO) as a High Activity Water Oxidation Photoanode

• Published in: ACS applied materials & interfaces 2021-08, Vol.13 (33), p.40127-40133
• Main Authors: Sheridan, Matthew V, McLachlan, Jeffrey R, González-Moya, Johan R, Cortés-Medina, Nicole D, Dares, Christopher J
• Format: Article
• Language: English
• Subjects: Materials Science; Science & Technology - Other Topics; Surfaces, Interfaces, and Applications
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c11298

Photochemical water oxidation was carried out at a mesoporous nanoparticle film composed of indium tin-doped oxide (nanoITO). Annealing nanoITO at temperatures above 250 °C affects both conducting and semiconducting properties. Impressive photoelectrochemical activity was observed at this degenerate n-type semiconductor electrode, outperforming the traditional semiconductor titanium dioxide (TiO2) under the same conditions. In a 0.1 M HNO3 solution, the nanoITO electrode sustained photocurrents of 1.0 mA/cm2 at an E applied = 1.5 V vs saturated calomel electrode (SCE) (η = 0.55 V) under a 90 mW/cm2 UV illumination (375 nm). This activity is compared to ∼0.3 mA/cm2 with a traditional TiO2 electrode under the same potential and conditions. Evidence for oxygen generation in the photolysis experiments was quantified using the collector–generator method, and >70% photocurrent efficiency for O2 production was confirmed at this nanoITO photoanode.