Synthesis and characterization of anodic WO3 layers in situ doped with C, N during anodization
By Zych, Marta; Syrek, Karolina; Pisarek, Marcin; Sulka, Grzegorz D.
Published in Electrochimica Acta
2022
Abstract
In this work, for the first time, anodic C,N-WO3 layers were obtained by in situ doping during anodic oxidation of metallic tungsten. The effects of applied potential (40, 50, and 60 V), and hexacyanoferrate (III) ion concentration (0, 15 and 60, 120, and 180 mM) in the electrolyte on the resulting oxide morphology, phase composition, and photoelectrochemical performance were investigated. To obtain a photoactive oxide phase, as-received samples were annealed at 500°C in air for 2 h. The synthesized materials were subjected to complex physicochemical characterization using SEM, EDS, XRD, and XPS. In addition, the semiconducting properties of prepared samples were characterized using the Mott-Schottky analysis. The anodic C,N-WO3 layers were used as photoanodes for water splitting experiments. The best photoelectrochemical performance was observed for the samples obtained in 1 M (NH4)2SO4 and 0.075 M NH4F with 120 mM K3[Fe(CN)6] at 50 V for 4 h.