Photoelectrochemical anodization for the preparation of a thick tungsten oxide film

• Published in: Electrochemistry communications Vol. 17; pp. 10 - 13
• Main Authors: Kim, Sunmi, Choi, Jinsub
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.04.2012; Amsterdam Elsevier; New York, NY
• Subjects: Anodization; Chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; Photoelectrochemistry; Photoelectrochemistry. Electrochemiluminescence; Tungsten oxide; Photoelectrochemistry; Tungsten oxide; Anodization; Phosphoric acid; Scanning electron microscopy; Transition metal; Nanoporous materials; X ray diffraction; Field emission microscopy; Surface structure; Electrodes; Inorganic acids; Transmission electron microscopy; Anodizing; Morphology; Preparation; Tungsten VI Oxides; Tungsten; Photoanodes; Photoelectric current; Photoelectrode
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2012.01.006

Nanoporous WO3 with a thickness of about 2.6μm was achieved by photoelectrochemical anodization; this thickness was around twice the thickness possible with normal (photo-absent) anodic film. The thickness increase is ascribed to the much formation of a protective crystalline oxide on the surface and acceleration of dissolution at the tip by holes generated during illumination. The nanoporous WO3 film prepared by photoelectrochemical anodization shows photocurrents of 1.85mA/cm2 in 0.33M H3PO4 under AM 1.5 illumination, a value nearly four times higher than that for film prepared with normal anodization. ► Photoelectrochemical anodization produces nanoporous WO3 with twice the thickness. ► The thickness increase is ascribed to the formation of a protective crystalline oxide. ► Dissolution at the tip is accelerated by holes generated during illumination.