Graphene-templated formation of two-dimensional lepidocrocite nanostructures for high-efficiency catalytic degradation of phenols

Abstract

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 (γ-FeOOH) nanosheets with high aspect ratio. We find that when reduced graphene oxide (rGO) was incubated with FeCl₃ of 20 wt% at 80 °C and in the presence of reducing reagents (e.g.hydrazine hydrate), close-spaced 2D nanosheets of γ-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), Mössbauer spectroscopy and synchrotron-based scanning transmission X-ray microscopy (STXM), which confirmed the formation of γ-FeOOH 2D nanosheets. Importantly, we explore the application of this novel nanomaterial as an efficient and stable catalyst for phenol treatment in wastewater.