Synthesis, Photoluminescence Properties, and Photocatalytic Activity of a Novel Y2O3/Co3O4 Nano-Composite Catalyst in the Degradation of Methyl Red Dye

Abstract

The Y2O3, Co3O4, and Y2O3/Co3O4 composites were synthesized by a microwave assisted polyacrylamide gel method and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), UV–Vis spectrophotometry, fluorescence spectrophotometry and electrochemical methods. XRD and FTIR results indicate that the Y2O3, Co3O4, and Y2O3/Co3O4 composites exhibits high crystallinity and no other diffraction peaks of impurities. SEM images show that the nanoscale metal oxides can be obtained by the microwave assisted polyacrylamide gel method. Optical properties show that the Co3O4 doping of Y2O3 causes large Eg change in Y2O3. Photoluminescence analysis reveals that the Y2O3 and Y2O3/Co3O4 composites possess obvious blue emission due to the surface defect present in the as-prepared samples. The effect of the catalyst content, dye concentration, pH value, and reaction temperature on the photocatalytic activity of the Y2O3/Co3O4 composites was systematically studied. Based on electrochemical test and photocatalytic experiment, the Y2O3/Co3O4 composites were confirmed to exhibit high photocatalytic activity in degradation of methyl red (MR) as a model dye. The photocatalysis mechanism of the Y2O3/Co3O4 composites is discussed on the basis of p‒n junction theory.