Study On The Preparation Of Sn_Zn_{（1-x）}WO₄Photocatalysts By Hydrothermal Synthesis And Its Photocatalysis Activity Under Visible Light Irradiation

Driven by solar energy, photocatalysis can react at room temperature and mineralize organic pollutants completely, which is an ideal environmental con trol and clean energy generation technology, and has broad application prospec ts. However, as photocatalyst has low visible light utilization rate, high electro n hole recombination rate and low quantization efficiency, the application of p hotocatalysis technology is highly limited. In oder to solve this problems, stud y on excellent photocatalyst material under visible light irradiation has importa nt signification.The paper takes SnWO4as research object, studies the preparation of Snx Zn(1-X)WO4composite visible light photocatalyst by hydrothermal synthesis met hod, and discusses the influence of different ratio of zinc to tin (mole ratio) and hydrothermal synthesis temperature and time on the property of photocatal yst. Then, character the composite photocatalyst by X-ray diffraction (XRD), s canning electronmicroscopy (SEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), Brunauer-Emmet-Teller (BET) surface area analysis methods a nd photocatalytic degradation of methyl orange dye.The research shows that the composite photocatalyst made has high photo catalysis activity, and the ratio of zinc to tin (mole ratio) and hydrothermal s ynthesis temperature and time also have different degree of influence on the property of photocatalyst. When mole ratio of zinc to tin is0.25, and hydroth ermal synthesis time is12h at100℃, there is best photocatalysis activity for the photocatalyst made, which has strong absorption peak in both UV-light a nd visible light with-1.74eV energy gap and77.9m2/g specific area.In order to demonstrate the composite photocatalyst performance, degradat ion of methyl orange dye test was made. The result shows that the main fun ction of decoloration is photocatalysis, which is influenced by dosage of phot ocatalyst, initial concentration of methyl orange dye, pH and salinity.The decoloration has high efficiency under neutral and acid conditions, a nd the difference in two conditions is small. The decoloration efficiency decre ased with the increase of methyl orange dye concentration. When initial meth yl orange dye is40mg/L, the optimal dosage of Sno.8Zno.2WO4is2.0g/L. S alinity lowers the decoloration efficiency, and the higher concentration of salin ity the higher inhibiting effect. In the range of test, the process obeys first-or der kinetic equation, and has highest efficiency at acidic condition. The comp osite photocatalyst made has high stability, and still maintains high photocatal ysis activity after five times reuse.