Photocatalytic Degradation Of Deoxynivalenol With Magnetic TiO₂-SiO₂ Inverse-opal Photonic Crystal Microsphere

Deoxynivalenol(DON)is a highly bioactive toxic secondary metabolite produced by the fusarium and yellow sickle bacillus,is produced predominantly in cereal products.There are many methods for the degradation of DON,but these have some disadvantages such as secondary pollutant generation,complex operation,large volume of reagent,and complicated pretreament.Therefore,it is very important to develop a fast,low cost,simple degradation method of DON.This paper proposes a photocatalytic degradation of deoxynivalenol with magnetic TiO2-SiO2 inverse-opal photonic crystal microsphere.First,the home-made microfluidic device was prepared by using the glass capillary,polytetrafluoroethylene(PTFE)tube and pipette gun head.The magnetic TiO2-SiO2 inverse-opal photonic crystal microspheres and TiO2-SiO2 inverse-opal photonic crystal microspheres were prepared by self-assembly method and high temperature calcination remove of polystyrene(PS)nanoparticle template.The experimental conditions for the preparation of microspheres were preliminarily studied by the results of metallographic and scanning electron microscopy.The results are as follows:PS,SiO2(5nm ultrafine SiO2 particles)and TiO2(5nm ultrafine TiO2 particles)concentrations were 8%,20%and 16%respectively;the ratio of TiO2-SiO2:PS=1:5(v/v);the concentration of Fe3O4 magnetic particles dispersion is at 0.15%wt;the ratio of TiO2:SiO2 = 1:6(v/v)and the ratio of TiO2:SiO2 = 1:9(v/v).The characterization results showed that the microspheres have good magnetic properties,bright color,smooth edges,part of regular structure.We have established a method for the photocatalytic degradation of deoxynivalenol based on magnetic TiO2-SiO2 inverse-opal photonic crystal microsphere.The magnetic TiO2-SiO2 inverse-opal photonic crystal microsphere and TiO2-SiO2 inverse-opal photonic crystal microsphere with different emulsion formula was exposed to 250W ultraviolet(UV)light.The photocatalytic properties of TiO2 was used to degrade DON and the degradation efficiencies of DON were detected by HPLC-DAD.Comparison of photocatalytic properties of microspheres with different emulsion formula,the results are as follows:the magnetic TiO2-SiO2 inverse-opal photonic crystal microspheres were prepared by the ratio of emulsion is TiO2:SiO2=1:6(v/v)was chosed as optimal group.DON could be reduced 49%within 5h.