Graphene oxide/titania hybrid films with dual-UV-responsive surfaces of tunable wettability

Abstract

Ultrathin hybrid films of graphene oxide (GO) and monolayer titania (TO) were assembled by layer-by-layer and drop-casting methods. The photo-induced wettability modulation of the hybrid films with different configurations was systematically studied. Due to the photocatalytic reduction of GO by TO, GO sheets in the hybrid films exhibited a tendency to undergo photo-induced conversion from hydrophilic to hydrophobic upon UV irradiation. On the contrary, TO nanosheets showed the reverse trend. Both surfaces of the hybrid film showed opposite yet tunable hydrophilicity under UV irradiation, demonstrating the potential for future application in liquid transport engineering.