The Preparation Of Yttrium Oxide Nanocomposite And Its Photocatalytic Performance

Photocatalytic technology has attracted much attention due to its advantages of simple operation,low cost,environmental protection and high efficiency.It is of great significance to design,synthesize and apply low-cost and highly efficient photocatalyst to realize the double environmental application of wastewater treatment and sterilization.As a semiconductor photocatalyst,rare earth oxide yttrium oxide has excellent chemical durability,thermal stability,corrosion resistance,photochemical stability and other characteristics,often applies in the field of photocatalysisIn this paper,two yttri-based nanocomposites,yttrium-ferric trioxide(Y2O3-Fe2O3)and yttrium-straw cellulose(Y2O3-SC),were prepared.The physical and chemical properties of the yttrium oxide nanocomposites were investigated by various characterization methods Staphylococcus aureus(ATCC 6538)and Escherichia coli(ATCC 8739)were selected as two target species.The photocatalytic antibacterial properties of the materials were studied by plate counting method and fluorescent staining test,and the effects of different cerium oxide nanocomposites,composite materials and illumination on the antibacterial properties of the materials and the antibacterial mechanism were investigated.Taking hexavalent chromium as the target pollutant,the effects of photocatalytic reduction of hexavalent chromium by composite materials were studied,and the effects of different proportions of composite materials,composite material concentration,hexavalent chromium concentration,pH and other environmental factors on the effects of photocatalytic reduction of hexavalent chromium by composite materials and the mechanism of photocatalytic reduction of hexavalent chromium were investigated(1)The Y2O3-Fe2O3 nanocomposites were prepared by hydrothermal method.The characterization results showed that the Fe2O3 particles were uniformly dispersed on the surface of Y2O3.The results of antibacterial experiments showed that the nanomaterials had good visible light catalytic activity against Escherichia coli and Staphylococcus aureus,and the antibacterial performance increased with the increase of illumination time.The antibacterial rate of 30 mg/L Y2O3-Fe2O3 to E.coli after 100 min illumination could reach 100%,while 60 mg/L Y2O3-Fe2O3 kill almost all Staphylococcus aureus after 60 min.The mechanism experiment results showed that h+ and ·OH were the main active components in the photocatalytic antibacterial process.(2)The results of photocatalytic reduction of hexavalent chromium showed that Y2O3-Fe2O3 nanocomposites had high performance of visible light photocatalytic reduction for Cr(VI).Under the conditions of pH 3 and material concentration of 0.8 g/L,the reduction rate of 5 ppm Cr(VI)and 10 ppm Cr(VI)can reach 100%and 98.9%respectively after 120 minutes of illumination,and the material had good stability and reproducibility.The experimental results showed that Y2O3-Fe2O3 nanomaterials can promoted the separation of photogenerated electron hole pairs during photocatalytic reaction,thus improving the reduction rate of Cr(VI).(3)Straw cellulose was prepared by TEMPO oxidation method,which was added into the hydrothermal synthesis system of yttria to prepare Y2O3-SC nanocomposite.SEM results showed that Y2O3 nano materials were well distributed on SC surface.Y2O3-SC nanomaterials had good antibacterial activity against Escherichia coli and Staphylococcus aureus under visible light irradiation.The antibacterial effect of 100 mg/L Y2O3-SC against Staphylococcus aureus reached 100%after 60 min of illumination.While the antibacterial effect of 30 mg/L Y2O3-SC on Escherichia coli could reach 100%after 30 minutes of light exposure.The experimental results of antibacterial mechanism showed that h was the main active component in the photocatalytic antibacterial system of Y2O3-SC nanocomposite.(4)The results of photocatalytic reduction of hexavalent chromium showed that Y2O3-SC nanomaterials have good photocatalytic reduction properties for Cr(VI)under visible light irradiation.Under the condition of pH 4 with the material concentration of 1.0 g/L,the reduction rate of 5 ppm Cr(VI)was 91.3%after 120 min of light,and the material had good stability and reproducibility.The experimental results of mechanism exploration showed that,in the process of photocatalytic reaction,e-was the main active substance in the process of photocatalytic reaction which played a key role in the reduction of Cr(VI).