Preparation of nanoporous BiVO4/TiO2/Ti film through electrodeposition for photoelectrochemical water splitting

A nanoporous BiVO4/TiO2/Ti film was successfully fabricated by electrodepositing a nanoporous BiOI film on nanoporous TiO2 arrays followed by annealing at 450°C for 2 h. The electrodeposition of BiOI film was carried out at different times (10, 30, 100, 500, and 1000 s) in Bi(NO3)3 and KI solution. The morphological, crystallographic, and photoelectrochemical properties of the prepared BiVO4/TiO2/Ti heterojunction film were examined by using different characterization techniques. UV-vis spectrum absorption studies confirmed an increase in absorption intensities with increasing electrodeposition time, and the band gap of BiVO4/TiO2/Ti film is lower than that of TiO2/Ti. The photocatalytic efficiency of BiVO4/TiO2/Ti heterojunction film was higher compared to that of the TiO2/Ti film owing to the longer transient decay time for BiVO4/TiO2/Ti film (3.2 s) than that of TiO2/Ti film (0.95 s) in our experiment. The BiVO4/TiO2/Ti heterojunction film prepared by electrodeposition for 1000 s fol...