Fe-doped SnO2 decorated reduced graphene oxide nanocomposite with enhanced visible light photocatalytic activity

Iron-doped tin oxide nanoparticles (Fe-doped SnO2 NPs), with different iron concentrations, were hybridized with reduced graphene oxide (rGO) through a three steps elaboration method to obtain Fe-doped SnO2/rGO nanocomposite. It was observed that the rutile structure of SnO2 is maintained even for high amounts of iron, as revealed by the X-ray diffraction (XRD) patterns that also indicated the reduction of the graphene oxide after the thermal treatment. Transmission electron microscopy (TEM) observations showed a uniform loading of the Fe-doped SnO2 NPs on the rGO sheets. The behavior of the absorbance, Fourier transform Infrared Spectroscopy (FTIR) and X-ray photoelectron emission (XPS) spectra of the as-synthesized Fe-doped SnO2/rGO composite further highlighted the reduction of GO during the preparation of the main heterostructure. The Raman spectroscopy revealed that both the intensity and the broadening of the G and D bands were affected by iron amount, suggesting a high interaction between the two components of the heterostructure. The photocatalytic efficiency of the elaborated nanocomposite was evaluated through the photodegradation of rhodamine B (RhB) under visible irradiation. It was found that the efficiency depended both on Fe concentration and GO amount. The experiments showed that 93% of RhB can be eliminated by the Fe-doped SnO2/rGO nanocomposite during the photocatalytic process. The photo-response of the Fe-doped SnO2/rGO seems to be the result of a synergistic effect between the two components of the main nanocomposite. Actually, in a first step, iron doping allows the photo-generation of electron-hole pairs from SnO2 NPs under visible irradiation, then, the excited electrons are trapped by the rGO sheets, which enhances the charge separation ability and further confirms the utility of such doped SnO2/rGO hybrids for photocatalytic applications. The reusability experiment for the elaborated composite was also carried out and the obtained results reveals a high cycling performance of the Fe-doped SnO2/ rGO heterostructure even under sunlight irradiation.