Multilayer Hybrid Films Consisting of Alternating Graphene and Titania Nanosheets with Ultrafast Electron Transfer and Photoconversion Properties

Alternating graphene (G) and titania (Ti0.91O2) multilayered nanosheets are fabricated using layer-by-layer electrostatic deposition followed by UV irradiation. Successful assemblies of graphene oxide (CO) and titania nanosheets in sequence with polyethylenimine as a linker is confirmed by UV-vis absorption and X-ray diffraction. Photocatalytic reduction of GO into G can be achieved upon UV irradiation. Ultrafast photocatalytic electron transfer between the titania and graphene is demonstrated using fermtosecond transient absorption spectroscopy. Efficient exciton dissociation at the interfaces coupled with cross-surface charge percolation allows efficient photocurrent conversion in the multilayered Ti0.91O2/G films