Structure And Photocatalytic Properties Of CNTs/Fe₃O₄@SiO₂-ZnO Composites

In this paper, CNTs/Fe₃O₄@SiO₂composite is synthesized by St ber methodusing magnetic carbon nanotube （CNTs/Fe₃O₄） as matrixes, then ZnO is assembledon the surface of CNTs/Fe₃O₄@SiO₂by polyol method to prepareCNTs/Fe₃O₄@SiO₂-ZnO composite. XRD，SEM，TEM，FTIR，XPS，PPMS，PL spectra and UV-visible spectra are carried out to study the structure,morphology and photocatalytic properties of the composite.It is found that, a layer of SiO₂is uniformly coated on the outside ofmagnetic carbon nanotube through St ber method, and ZnO particles aresuccessfully assembled on the surface of CNTs/Fe₃O₄@SiO₂composite by polyolmethod using zinc acetate as precursor. The loading content of ZnO increases asthe amount of zinc acetate increases.According to the research on the effect of ZnO loading amount, pH valueand initial methyl orange concentration on the photocatalytic properties ofCNTs/Fe₃O₄@SiO₂-ZnO composite,The Photo-catalyticProperty of the compositesis becoming better and better with increasing the loading amount of ZnO,decreasing the pH as well as the initial concentration of methyl orange.Thebest photocatalytic property of CNTs/Fe₃O₄@SiO₂-ZnO is observed when,theCNTs/Fe₃O₄@SiO₂/zinc acetate ratio is1:4,pHvalue is4and initial concentrationof methyl orange is5mg/L,respectively. At the same time, recycling photocatalyticexperiment by magnetically recycled photocatalyst show that, the compositemaintain high photocatalytic activity in10cycles.This indicates thatCNTs/Fe₃O₄@SiO₂-ZnO is a kind of easily recover and recyclable photocatalyst.The kinetic results indicate that the photocatalytic degradation reactions ofCNTs/Fe₃O₄@SiO₂-ZnO composite with different ZnO loading amount, pH valueand initial methyl orange concentration, follow the kinetic rule of first orderreaction. The reaction rate constants increase with the increasing ZnO loadingamount and pH value of methyl orange solution decreases with the increase ofmethyl orange concentration.