Fabrication of tungsten trioxide photoanode with titanium microfibers as a three dimensional conductive back contact

• Published in: Materials letters 2017-07, Vol.199, p.68-71
• Main Authors: Amano, Fumiaki, Shintani, Ayami, Tsurui, Kenyou, Hwang, Young-Min
• Format: Article
• Language: English
• Subjects: Conductivity; Heat treatment; Immersion coating; Materials science; Microfibers; Microstructure; Nanocrystalline materials; Nanoparticles; Photoanodes; Semiconductor electrodes; Solar energy materials; Thin films; Tungsten oxide; Tungsten oxides
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2017.04.051

[Display omitted] •Polyethylene glycol 20,000 provides a viscous solution for dip coating.•Thermally stable Ti microfibers enable heat treatment in air at 650°C.•Porous microfibers increased loading amount of WO3 nanoparticles.•High photocurrent density was achieved by 3-D electrical contact.•Visible-light response was increased by the enhanced photoabsorption. Ti microfibers with a diameter of 20μm were used as a three dimensional conductive back contact for a tungsten oxide (WO3) photoelectrode. We coated the microfibers with WO3 nanoparticles by a solution-based dip coating step and heat treatment at 650°C. A high loading of WO3 nanoparticles was achieved over a large surface area of the porous microfibers through the use of a high viscosity solution for the dip coating. The prepared WO3-coated Ti microfibers exhibited enhanced photoelectrochemical properties. Visible light response was improved in the conductive Ti microfibers owing to increased absorption of visible light and efficient extraction of photoexcited electrons at the large interface.