Synthesis and photocatalytic properties of the graphene–La2Ti2O7 nanocomposites

Graphene–La2Ti2O7 nanocomposites used as photocatalyst were prepared via a two-step process in this paper. Graphite oxide was firstly exfoliated via thermal expanding process under 1000 °C, then the expanded graphite was reduced by La2Ti2O7 nanosheets under UV light irradiation. The as-prepared graphene–La2Ti2O7 nanocomposites were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), BET surface area analyzer, Raman spectroscopy, Fourier transformation infrared (FTIR) spectroscopy and UV–vis diffuse spectroscopy. The composites exhibited an enhanced photocatalytic activity for decomposition of rhodamine B (RhB) under UV-irradiation compared to pure La2Ti2O7 materials, which was attributed to the increase in the charge separation efficiency in the presence of graphene and the large surface contact between graphene and La2Ti2O7.

► Well-distributed graphene–La2Ti2O7 nanocomposites have been obtained.
► The composites exhibited an enhanced photocatalytic activity for decomposition of rhodamine B.
► The presence of graphene effectively suppressed the charge recombination and enhanced the charge separation efficiency of La2Ti2O7 photocatalysts.