Study on photocurrent of bilayers photoanodes using different combination of WO3 and Fe2O3

Bilayer photoanodes were prepared onto glass substrates (FTO) in order to improve generated photocurrents using UV-vis light by water splitting process. A comparative study of photocatalytic was performed over the films surface using Fe2O3, WO3 and mixture of bicomponents (Fe2O3:WO3). Different types of films were prepared using Fe2O3, WO3 and bicomponents (mixture) on FTO substrates. The films were grown by sol gel method with the PEG-300 as the structure-directing agent. The photo-generated of the samples were determined by measuring the currents and voltages under illumination of UV-vis light. The morphology, structure and related composition distribution of the films have been characterized by SEM, XRD and EDX respectively. Photocurrent measurements indicated surface roughness as the effective parameter in this study. The deposited surfaces by bicomponents or mixture are flat without any feature on the surface while the deposited surfaces by WO3 appears rough surface as small round (egg-shaped particles) and cauliflower-like. The surface deposited by Fe2O3 show rough no as well as WO3 surface. The deposited surfaces by WO3 reveal the higher value of photocurrent measurement due to surface roughness. Indeed, the roughness can be effective in increasing contact surface area between film and electrolyte and diffuse reflection (light scattering effect). The solution (Fe2O3:WO3) shows the low photocurrent value in compare to WO3 and Fe2O3 hat it may be due to decomposition the compound at 450 ± 1 °C to iron-tungstate Fe2(WO4)3.