Photoelectrochemical activity of WO3/Au in aqueous electrolyte with addition of methanol

Tungsten trioxide (WO₃) thin films were prepared on fluorine-doped tin oxide (FTO) substrate by electrodeposition method using peroxotungstic acid with pH 1.3 as the electrolytes. The as-deposited sample was calcined at 350°C. The gold (Au) loading on WO₃ films was carried out by using the sputtering method with a different sputtering time of 1s and 5s. The photoelectrochemical activities of bare WO₃ and WO₃/Au with different Au loading in 0.5 M Na₂SO₄ with and without addition 0.2 M methanol were studied. The linear scan Voltammetry in three electrode system was employed and the photocurrent generated was presented. The electrode prepared with Au loading shows higher photocurrent compared with WO₃ alone. Meanwhile, photocurrent with the addition of methanol in the electrolyte is higher compared to the electrolyte without the addition of methanol. The structural properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and the absorption of light was measured using UV-Vis spectrophotometer. It has shown that the structure, thickness, crystallinity, and the band gap of WO₃ does not change with Au loading.