Nanohybrids of 1D tin oxide (SnO2) nanotubes 2D-reduced graphene oxide (RGO) for improving photodegradation of Cr(VI)

A series of 1D tin oxide (SnO2) anchored on the 2D-reduced graphene oxide (RGO) composites were successfully synthesized by two-step hydrothermal method. The microstructure, morphology, chemical composition, oxidation states and surface areas of SnO2 nanotubes, SnO2 nanotubes/RGO nanosheets were comparatively studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). UV-Vis absorption spectra indicate that SnO2@RGO nanohybrids enhance absorbance in UV as well as visible region, while the intensity of PL decreases as compared to SnO2. This plays a crucial role to minimize the recombination of charge carriers through transfer of electron from SnO2 to RGO. The photocatalytic activities of the as-prepared nanocomposites for the photoreduction of Cr(VI) under visible irradiation were investigated. The SnO2@RGO nanocomposites exhibited better photodegradation efficiency (98%) than the bare SnO2 (38%). The enhanced photocatalytic activity of SnO2@RGO can be attributed to vectorial electron transfer process in the continuous network of RGO with large specific surface area, synergistic interaction between RGO and SnO2.