The Synthesis, Characterization And Photocatalytic Activity Of Ternary Heteropoly Anion Layered Compounds

Zn2Al clay was synthesized by coprecipitation method. Four kinds of ternary heteropoly salt were synthesized by direct synthesised method, they were K7[Zn(H2O)CrW11O39], K7[Cu(H2O)CrW11O39],K8[Cu(H2O)NiW11O39] and K8[Cd(H2O)NiW11O39]. And four kinds of heteropoly anion layered compounds were synthesized by ion exchanged method, they were LDH-ZnCrW11, LDH-CuCr W11, LDH-CuNi W11 and LDH-CdNi W11. The phase composition, stuctures and morphologies of the four kinds of heteropoly anion layered compounds were characterized by Fourier transform infrared(FT-IR) spectrum, X-ray diffraction(XRD)patterns, N2 adsorption-desorption tests and scanning election microscopy assisted X-rad enerey dispersive spectroscopy(SEM-EDS). The results showed that ternary heteropoly anions with their original Keggin structure were successfully inserted into the Zn2 Al clay.Photocatalytic activity of ternary heteropoly anion layered compounds was studied by this experiment. The photocatalytic degradation experiment of methylene blue and malachite green were studied by four kinds of heteropoly anion layered compounds catalysts. and 30 W UV lamp was regard as light source. The effect of several different conditions, such as pH, dosage of catalyst and initial concentration on decolorization of methylene blue and malachite green were studied, and the best conditions were successfully identified. Finally, their photocatalytic activity was compared with their corresponding heteropoly salt and clay in the best conditions. The experimental results showed that the photocatalytic activity of layered compounds was much higher than their heteropoly salt and Zn2 Al clay, like this, the order of the photocatalytic activity was that: layered compounds > heteropoly salt > Zn2 Al clay.