Improved photocatalytic activity of RGO/MoS2 nanosheets decorated on TiO2 nanoparticles†
In this work we have synthesized a heterogeneous hybrid junction of reduced graphene oxide (RGO)/MoS2 and hybrid composites of TiO2–RGO/MoS2 using a hydrothermal method. The hybrid composites were characterized using UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and electron paramagnetic resonance spectroscopy (EPR). Raman spectroscopy displays that the hybrid junction was formed between two dimensional RGO and few layer MoS2 nanosheets. In the TiO2–RGO/MoS2 hybrid composite, EPR studies show that the lattice Ti3+ signal was decreased and at the same time equivalent amounts of the O˙− signal increased under UV light irradiation. These results suggested that the interfacial charge transferred from the TiO2 surface to the MoS2 surface active sites directly or through the RGO nanosheets toward suppressing the recombination rate of the electron–hole pairs for an enhanced methylene blue degradation. RGO behaves like a conductor, it accepted only electrons and transported to the active sites through separating the potential level distance between the two semiconductors.