Preparation,Characterization And Photocatalytic Properties Of Polyoxometalate /PANI/ZrO₂ Composite

In this paper,the two kinds of polyoxometallates are prepared by direct synthetic method,namely K₈[Fe（H₂O）CdW₁₁O₃₉],K₈[Cu（H₂O）ZnW₁₁O₃₉].The intermediate of PANI/ZrO₂ is prepared by chemical oxidation method with（NH4）2S2O₈ as an oxidant to form polyaniline-doped ZrO₂,and then the two kinds of new composite materials are prepared by electrostatic self-assembly method of K₈[Fe（H₂O）CdW₁₁O₃₉],K₈[Cu（H₂O）ZnW₁₁O₃₉] and i n t e r m e d i a t e PA N I / Z r O₂,n a m e l y K₈[ F e（H₂O）C d W1 1O3 9] / PA N I / Z r O₂,K₈[Cu（H₂O）Zn W₁₁O₃₉]/PANI/Zr O₂.The composition structure and morphology of above s a mp l e s a r e c h a r a c t e r i z e d b y F T-I R,UV-v i s,X R D,X P S,T G,S E M-E D S a n d N₂ dsorption-desorption.The results indicate that: the two kinds of polyoxometallates K₈[Fe（H₂O）CdW₁₁O₃₉] and K₈[Cu（H₂O）Zn W₁₁O₃₉] have been successfully compounded to intermediate PANI/ZrO₂,which present flaky surface morphology,possessed well crystalline structure and kept the original Keggin structure of two kinds of polyoxometallates K₈[Fe（H₂O）Cd W1 1O3 9],K₈[C u（H₂O）Zn W1 1O3 9].To investigate the photocatalytic activities of above two composite materials,the related experiments had been carried out.The photocatalytic activities of above two composite materials were studied for photocatalytic degradation of malachite green dyestuff and xylenol orange solution as a model.The effect of initial concentration,initial pH value of dye solution and catalyst dosage were studied.The optimum light degradation conditions were determined.In addition,the activities of different catalysts were compared and the recovery and recycling value of catalysts were also explored.The results indicated that K₈[Fe（H₂O）CdW₁₁O₃₉]/PANI/ZrO₂ and K₈[Cu（H₂O）ZnW₁₁O₃₉]/PANI/ZrO₂ had high photocatalytic activity,and its photocatalytic activity was superior to other catalysts,secondary repeated use of the catalyst still had certain photocatalytic ability.Furthermore,the dynamic of the two dyes were discussed,the results showed that photodegradation conformed the first-order kinetics equation.