SnO2/reduced graphene oxide nanocomposites for highly efficient photocatalytic degradation of methylene blue

SnO2/reduced graphene oxide (rGO) nanocomposites were prepared by one-step hydrothermal method. The structure, particle size, morphology, and phase composition of SnO2/rGO nanocomposites were studied by X-ray diffraction, field-emission scanning electron microscopy, and Raman scattering spectroscopy measurements. Results showed that SnO2 nanoparticles had a rutile crystal structure and average crystallite sizes of 4.60, 5.24, and 5.60 nm for SnO2, SnO2/rGO-1%, and SnO2/rGO-2% samples, respectively. Raman scattering spectra showed the coexistence of two SnO2 and rGO phases in nanocomposites, and the reduction of GO to rGO increased when the GO concentration increased from 1% to 2%. The absorption properties and the Eg band gap value were studied through UV–vis absorption spectra. The absorption spectra showed a characteristic absorption peak of SnO2 at 296 nm, and the visible region absorption increased with rGO doping. In addition, the band gap of SnO2/rGO nanocomposites decreased with rGO doping. The photocatalytic properties of SnO2/rGO nanocomposites were studied using the decomposition of methylene blue (MB) under visible light. Results showed that SnO2/rGO nanocomposites decomposed MB by more than 90%, while SnO2 decomposed MB by only approximately 30%, proving that rGO has the effect of enhancing the photocatalytic degradation of SnO2/rGO nanocomposite.