Synthesis of visible-light-responsive Fe(III)-doped TiO2 films using graphene oxide-based composite sheets as sacrificial building blocks

Abstract

Graphene oxide sheets have been utilized as both carriers and sacrificial building blocks to prepare freestanding Fe(III)-doped TiO2 composite films. First, graphene oxide sheets are decorated by TiO2 particles, and the as-obtained products are further modified by Fe(III) precursors, forming relatively uniform composite sheets. Assembling of these composite sheets enables different substances (Ti and Fe) to be distributed uniformly in the as-formed bulk films, which results in the formation of homogeneous freestanding Fe(III)-doped TiO2 composite films under calcinations. Furthermore, the contents of Fe(III) in TiO2 films can be controlled easily by adjusting deposition amount of Fe(III) precursors in graphene oxide-TiO2 composite sheets. UV–vis diffuse reflectance results and photocurrent tests indicate that addition of Fe can enhance visible light responses of TiO2 films. At certain doping amount of Fe(III), the as-prepared TiO2 films display the strongest photocurrent signals under visible light irradiation.