▎ 摘　　要

Graphene is a two-dimensional nanomaterial with exceptionally interesting physical and chemical properties, which has been actively explored in nanoelectronics, nanodevices and nanoscale catalysis. Here we report a graphene-templated route toward mild, solution-phase synthesis of ultrathin single crystal lepidocrocite (gamma-FeOOH) nanosheets with high aspect ratio. We find that when reduced graphene oxide (rGO) was incubated with FeCl(3) of 20 wt% at 80 degrees C and in the presence of reducing reagents (e. g. hydrazine hydrate), close-spaced 2D nanosheets of gamma-FeOOH was formed on the surface of rGO, with the average thickness of 2.1 nm. This ultrathin nanomaterial was characterized via a range of complementary techniques, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Mossbauer spectroscopy and synchrotron-based scanning transmission X-ray microscopy (STXM), which confirmed the formation of gamma-FeOOH 2D nanosheets. Importantly, we explore the application of this novel nanomaterial as an efficient and stable catalyst for phenol treatment in wastewater.