Microwave-assisted Preparation Of Copper Zirconium Phosphate And Its Application

The synthesis and application of zirconium copper phosphate?ZPCu?,a kind of phosphate complex salt,is seldom reported.The reported zirconium copper phosphate is always prepared by Cu²⁺/H+ ion exchange using hydrothermal method.However,the morphology is difficult to be controled which is usually performed under high temperature,high pressure and long reaction time.Microwave-assisted heating method is a new green synthetic method for nano-material with narrow distribution of particle size,good dispersibility and special morphology.The microwave non-thermal effect can also affect the formation of crystal shape.However,there is no report about the preparation of zirconium copper phosphate using microwave-assisted heating method.In this paper,the preparation of zirconium copper phosphate was one-step prepared by a microwave-assisted heating method under low temperature?<100??and normal pressure.A special morphology zirconium copper phosphate was prepared by microwave-assisted heating method using ZrOCl₂,NH₄F,CuCl₂ and NaH₂PO₄ as raw materials and water as solvent.The influence of p H values,reactant concentrations,microwave heating temperature and time,n?Cu?:n?Zr?and n?F?:n?Zr?on the formation and morphology of ZPCu were studied.The result shows that the morphology and crystallinity were significant influenced by the mentioned condition.ZPCu assembled coil-like with uniform size can be prepared under reaction condition:[Zr⁴⁺]=0.005mol·L-1,[Cu²⁺]/[Zr⁴⁺]=1,[F^-]/[Zr⁴⁺]=6,[PO₄^3-]/[Zr⁴⁺]=20,pH=4.8,90? and 30 min.There are three stages in thermal weight loss process of ZPCu,they are 55⁷5?,75¹22?and 122²60?,respectively loss one,two and one crystal water.Phase transition of ZPCu would be occurred after calcinated at 800?.In addition,microwave absorbing property of ZPCu was also investigated.The result shows that ZPCu behaves a little absorbing property,the reflectivity is below-10 d B at the frequency range from 2GHz to 18 GHz,and the lowest reflectivity is-10.74 d B at 15.6GHz.Photocatalytic properties and behavior in heterogeneous Fenton-like system of ZPCu under illumination were evaluated by degrading model pollutant rhodamine B?Rh B?.ZPCu as a photocatalyst in the experiment,using HCl and Na OH adjusts p H,then,adding a certain volume of H₂O₂ after absorption and desorption equilibrium.This experiment reacts under illumination and room temperature?10¹5??.The results revealed that ZPCu exhibited a little photocatalytic activity under ultraviolet and visible light,the catalytic efficiency enhanced obviously with addition of H₂O₂.The degradation rate of the dye enhanced with the increasing dosage of ZPCu and H₂O₂.ZPCus with different morphologies have different photocatalytic properties,the order photocatalytic activity of ZPCu at the presence of H₂O₂ is: coil-like > flame-like > flaky.The system showed the best photocatalytic activity at p H values between 5.0 to 9.0.In this paper,the degradation performance of ZPCu-H₂O₂ system under heating was studied.ZPCu as a photocatalyst in the experiment,catalyzed H₂O₂ to degrade Rh B solution under heating.The result shows that Rh B 5.0×10-5mol·L-1,the dosage of ZPCu 0.03 g,30%H₂O₂ 0.5m L,the reaction system was heated at 50? for 10 min,the decolorization of Rh B could reach 97.1%.Degradation property of this system increased with increasing temperature and the dosage of ZPCu and decreasing the initial concentration of dye.ZPCu exhibited excellent stability and effectiveness after 5 consecutive runs in terms of degradation of Rh B.The degradation rate still reached 85% after 5 runs.In conclusion,a simple,efficient and eco-friendly synthetic method for ZPCu was obtained in this paper.Compared with traditional hydrothermal method,the microwave-assisted synthetic method of ZPCu shorted the reaction time and improve efficiency.The photocatalytic properties and behavior in heterogeneous Fenton-like system of ZPCu were discussed,it would wide the application fields ZPCu.