Enhanced photocatalytic degradation of methyl orange using Sn-ZnO/GO nanocomposite

Abstract

Sn doped ZnO nanoparticles was synthesized by a sol-gel approach using different concentrations of Sn to afford ZnO-Sn(5%), ZnO-Sn(10%), and ZnO-Sn(20%). The ZnO-Sn(10%) was further composited with graphene oxide to form Sn-ZnO/GO for the photocatalytic degradation of methyl orange (MO). The doped ZnO and nanocomposites were characterized by using X-ray diffraction, scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), transmission electron microscopy (TEM), UV–vis, and fluorescence spectroscopy. XRD analysis confirmed the successful incorporation of ZnO-Sn(10%) into the GO. The diffraction patterns of the Sn-ZnO/GO nanocomposites were similar to that of the doped samples, which suggested the destruction of the layered structure of GO during the synthesis. A quasi-spherical morphology was confirmed at the different percentages of the materials formed by the SEM and TEM analyses. The microscopic analysis also revealed that the ZnO-Sn(10%)/GO nanocomposites have rough surfaces, with Sn and Zn ions uniformly dispersed among the GO sheets. Optical studies showed a reduction in the photoluminescence of the doped nanoparticles compared to the pristine ZnO, with most pronounced reduction obtained in the ZnO-Sn(10%) system. Hence, was used for the formation of composite and photocatalytic degradation studies. The performance of the photocatalyst was evaluated in the degradation of MO, and some process parameters such as influence of ZnO modification regime, initial dye concentration, and effect of catalysts dose were studied. The ZnO-Sn(10%)/GO photocatalyst exhibited an efficiency of about 96.2% within 2 h irradiation time using optimum dose and initial MO concentration of 100 mg and 50 mg/L respectively. However, the application of Sn-ZnO/GO nanocomposites to remove other pollutants could establish the efficiency of this product.