Composite WO3–TiO2 films: Pulsed electrodeposition from a mixed bath versus sequential deposition from twin baths

Composite WO3–TiO2 semiconductor films were cathodically electrodeposited using sequential deposition of WO3 and TiO2 from aqueous baths containing peroxytungstate and titanyl precursor species, respectively. The composite films were prepared by switching the baths for five cycles of deposition at −0.45 V (for WO3) and −0.95 V (for TiO2). These new films were compared and contrasted with composite WO3–TiO2 films prepared by pulsed electrodeposition from a mixed bath. Neat WO3 films were also included for this comparison; the best photoelectrochemical response was shown by the composite films obtained from the new procedure.