Preparation Of Magnetic Cubic-CuFe₂O₄ Nanofiber And Its Photocatalytic Performance Study

CuFe₂O₄ is a super-paramagnetic semiconductor with strong capability of light absorption and better conductivity.CuFe₂O₄ has good practical values in many fields,such as magnetic storage device,sewage treatment agent and gas sensitive material.CuFe₂O₄ has two crystalline forms?tetragonal form and cubic form?.At present,different morphology of tetragonal-CuFe₂O₄ has been prepared through the hydrothermal method,coprecipitation method and electro-spinning method in the reported studies.However,researching a new method to prepare diversified cubic-CuFe₂O₄?c-CuFe₂O₄?in photocatalytic performance is still of great significance.CuFe₂O₄ has a very narrow energy band,which is only about 1.56 eV,making the electron-hole pairs recombine quickly and decreasing the oxidation-reduction efficiency of organic matter effected by photo-carriers.Nanomaterials can be better applied in real life through morphology,heterojunction and defect control.Among the control methods,the study of heterojuntion control is particularly active.To solve above problems,this paper demonstrated the c-CuFe₂O₄ nanofibers with photocatalytic performance.Then through the chemical coprecipitation method,we combined c-CuFe₂O₄ nanofibers with ZnO to form p-n heterojunction.We also embedded the Ag particles in the fibers to form Ag/semiconductor heterojunction.Hence,the photocatalytic performance of c-CuFe₂O₄nanofibers and the structure stability of heterojunction were enhanced.The main works are as follows:?1?The c-Cu Fe₂O₄ nanofibers were successfully prepared via electrosipping assisted and subsequent heating in low temperature by citric acid.The fibers had a better aspect ratio and were composed of many c-CuFe₂O₄ nanoparticles about 10-20 nm in size.The results showed that c-CuFe₂O₄ nanofibers had the photocatalytic performance under visible-light irradiation.Since the c-CuFe₂O₄ nanofibers had the super-paramagnetic,the samples could be recollected with a magnet after photocatalytic process,avoiding secondary pollution of treated water effectively.?2?The p-n heterojunction of c-CuFe₂O₄/ZnO nanofibers?c-CFZs?were prepared by the chemical coprecipitation.It was found that the ZnO particles were coated on the surface of c-Cu Fe₂O₄ nanofibers.The visible-light-driven photo-degradation activities of c-CFZs were demonstrated to be superior to the pure c-CuFe₂O₄ and ZnO.Hence,c-CFZs not only improved the photocatalytic performance of single c-CuFe₂O₄nanofibers,but also improved the problems about photocatalytic application under visible light and sample's recovery of ZnO.?3?The Ag?NO?₃ was added in the precursor solution of c-CuFe₂O₄ nanofibers preparation,then the c-CuFe₂O₄/AgO nanofibers?c-CFAs?were fabricated by electrosipping.It was found that the mental Ag exhibited an efficient plasmon resonance behavior in the visible light,which could be utilized to form doping level in the c-CuFe₂O₄ semiconductor and speeded up the separation efficiency of photo-generated carriers.The photocatalytic performance of c-CFAs exhibited a trend of decreasing with the increasing of Ag/Fe molar ratio.And when Ag/Fe molar ratio reached 0.25,the optimum performance achieved.Meanwhile,compared with the structure stability of c-CFZs,c-CFAs overcame the photo-corrosion effect of ZnO in the photocatalytic process,which decreasing the cyclic derating rate of composite fibers.