Effect of Nanographene Platelets in Transition Metal-doped ZnO for Photocatalytic Application

Both doping and combining ZnO nanoparticles with iron and nanographene platelets (NGP), respectively, have been successfully conducted using the co-precipitation method with various loadings of NGP. The differential thermal analysis and thermogravimetric analysis (DTA/TGA) showed weight loss from the as-prepared samples owing to boundwater and adsorbed water elimination and the combusted effect of NGP in the samples. The structure and morphology or X-ray diffraction (XRD) characterization of the Fe-doped ZnO/NGP nanocomposites exhibited hexagonal wurtzite structure from ZnO and graphite structure from NGP. Raman spectroscopy was also used to observe the frequency modes of the samples. The Fourier transform infrared (FTIR) spectroscopy indicated that increasing NGP amount could decrease the intensity of Fe-O and ZnO vibration mode peaks on the absorption spectra. The photocatalytic test results indicated that certain weight percentage (wt.%) of NGP could enhance the performance of Fe-doped ZnO to degrade methylene blue dye in an aqueous solution under UV light irradiation. To obtain the main active species in the photocatalytic activity, additional scavengers were added in the solution. We also varied the dye and dosage concentration to determine the maximum condition in the photocatalytic process.