context: The ITO-coated glass samples were cleaned with acetone, ethanol, and isopropanol, sequentially. The vacant assemblies were prepared by using two ITO-coated glass samples with and without WO3 layers, respectively, which were stacked with a 60 μm-thick Surlyn adhesive film. Then, two electrolyte inlets were drilled into the ITO-coated glass side without the WO3 layer. The prepared electrolyte was injected into the vacant assemblies, and the inlets were closed. All the working areas were of 2.34 cm2 (1.3 cm × 1.8 cm). Finally, the filled assemblies were subjected to UV irradiation at a wavelength of 360 nm for periods of 0, 5, 10, and 20 min.