Research On Synthesis, Charaterization And Photocatalytic Activity Of Transition Metal Substitute Of Polyoxometalates

With the fast industrial development, kinds of hazardous pollutants have entered environment. Especially the great increase of industrial wastewater that underlined the pollution in aqueous environment and jeopardized the environment critically. Due to their low concentration, stable structure, and being difficult to degrade biologically, some poisonous organic pollutants can hardly be removed by traditional method. Photocatalytic degradation, a new method of disposing wastewater developed in recent thirty years, features stable reaction, good degradation effect, and non-secondary pollution.This paper synthesized eight phosphotungstic series of heteropoly complexes, which are substituted by the transition elements composing K_n[PW₉V₂O₃₉Z(H₂O)] (Z = Zn, Cd, Cr, Mn, Fe, Ni, Co, Cu). When such series of compounds and the modified sign are loaded, eight heteropoly complexes of compound catalytic materials (abbreviation as PW₉V₂Z/Resin) (Z = Zn, Cd, Cr, Mn, Fe, Ni, Co, Cu) were produced. In addition, we carried out analytical determination and characterization for the 16 heteropoly compound catalytic material agents by a series of analytical methods such as Infrared spectroscopy, UV - visible absorption spectroscopy, X-ray powder diffraction analysis, scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that the synthesized heteropoly compound series remain as Keggin-type structure; Composite materials are bonded with the modified load through the Z-N coordination bond.This paper studied photocatalytic degradation for Rhodamine B solution under UV irradiation on the condition that Rhodamine B is taken as model organic dye pollutants, which used synthetic 16 kinds phosphotungstic series of heteropoly complexes and composite materials as photocatalyst, by changing the illumination time, catalyst type, catalyst concentration and pH, and other factors catalytic conditions. The results show that phosphotungstic series of heteropoly compounds which are substituted by the transition elements have good catalytic activity, and the maximum degradation rate is up to 92%; the catalytic effects of eight kinds are more than 80% under homogeneous system; the maximum degradation rate is up to 70% in 60min under non-homogeneous system.