Enhanced visible photocatalytic activity of Fe‐Cu‐ZnO/graphene oxide photocatalysts for the degradation of organic dyes

Abstract

AbstractFe‐Cu‐ZnO/graphene oxide (Fe‐Cu‐ZnO/GO) photocatalysts are successfully prepared by the sol‐gel method and characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectrometry (FTIR), UV‐Vis diffuse reflectance spectra (UV‐Vis DRS), and X‐ray photoelectron spectroscopy (XPS). The results show that the Fe‐Cu‐ZnO/GO photocatalyst has the smaller average crystallite size and the narrower band gap, exhibits the stronger light absorption in the whole visible light region, and possesses better charge separation capability than that of pure ZnO, ZnO/GO, and Cu‐ZnO/GO photocatalysts. The photocatalytic activity of these catalysts is tested by degradation of dark green dye under visible light irradiation which demonstrates that Fe‐Cu‐ZnO/GO photocatalyst effectively degrades dark green dye and shows a significant photocatalytic enhancement compared to ZnO, ZnO/GO, and Cu‐ZnO/GO photocatalysts. The degradation rate of dark green dye can reach up to 99.28 %, when the initial concentration of dark green dye is 50 mg/L and the Fe‐Cu‐ZnO/GO catalyst dosage is 1 g/L with neutral pH under 90 min of visible light irradiation. In addition, Fe‐Cu‐ZnO/GO photocatalyst shows a good degradation efficiency on three other dyes. Meanwhile, the catalyst shows relatively superior reusability according to the cycling tests.