K/Al-doped ZnO nanocomposite as bifunctional catalyst for photocatalysis and synthesis of dimethyl carbonate

Abstract

In this paper, K/Al-doped ZnO nanocomposite was prepared by coprecipitation and impregnation method using sodium hydroxide as precipitation agent. The title material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV–Vis), Brunauer-Emmett-Teller (BET) and temperature-programmed desorption of carbon dioxide (CO2-TPD). K/Al-doped ZnO as photocatalyst exhibits highly efficient photocatalytic performance for degradation of four typical dyes (Methylene blue (MB), Congo red (CR), Rhodamine B (RhB) and Methyl orange (MO)) under UV-light irradiation. The photocatalytic decomposition rate in the order of CR (91.40%) > MB (82.47%) > RhB (54.96%) > MO (51.70%). The comparative experiments show that K/Al-doped ZnO composite possesses higher activity relative to ZnO, Al2O3 and Al-doped ZnO. Furthermore, the composite also has unique catalytic behavior for the one-pot synthesis of dimethyl carbonate (DMC) from methanol (MeOH), epoxy propane (PO) and CO2, which may be an effective and simple material to one-pot synthesize DMC in industry.