可磁性分离光催化剂的制作

Preparation of Magnetically Separated TiO_2(shell)/Ni-Cu-Zn Ferrite(core) Photocatalyst

纳米TiO2(壳)/Ni-Cu-Zn ferrite(核)核-壳结构复合材料,具有纳米TiO2光催化剂的特性与优点,且兼有ferrite强磁性以便利用外加磁场达到回收光催化剂再利用的效果。Ni-Cu-Zn ferrite磁粉是利用电镀镍,电镀铜,电镀锌及钢板酸洗废液以化学共沉法制作成8—20 nm的磁粉,再经900℃1 h热处理增强其磁性而成约80 nm的磁粉。利用此磁粉作为结晶核,先加入TiO(SO4)溶液,再以NH4OH调整pH值至6—7,使其产生Ti(OH)4胶态沉淀,加热搅拌使之均匀混合,经过滤后进行不同热处理使之成为纳米TiO2(壳)/Ni-Cu-Zn ferrite(核)核-壳结构复合材料,可重复多层被覆TiO2(壳)。经XRD检测其晶相随多层被覆,Ni-Cu-Zn ferrite尖晶石结构愈来愈弱而TiO2锐钛矿结构愈来愈强。由SEM观察其颗粒大小由约80 nm成长至120 nm。

Nano-TiO2（shell）/Ni-Cu-Zn ferrite （core） core-shell composite had the properties and advantages of nano-TiO2 photocatalyst and ferromagnetic property of Ni-Cu-Zn ferrite in order to recycle and reused the photocatalyst with external magnetic field. Ni-Cu-Zn ferrite powder with particle size of 8-20 nm was prepared from the electroplating waste solutions and steel pickling liquor by chemical coprecipitation method and was annealed at 900℃ 1 h to increase the saturation magnetization （Ms） and make the particle size increase to about 80 nm. The annealed Ni-Cu-Zn ferrite powder was used as crystallization nuclei, TiO（SO4） solution and water was added into. Then NH4OH solution was added into to adjust the pH of 6-7, Ti（OH）4 gel precipitate. Before filtering, Ni-Cu-Zn ferrite powder and Ti（OH）4 gel in the solution must be agitated and mixed completely. After filtering, the mixture of Ni-Cu-Zn ferrite powder and Ti（OH）4 gel was calcinated at different temperatures. More coatings could be made in the same process. From the XRD patterns of the composite, the stronger the crystalline structure of TiO2 （Anatase） and the weaker the crystalline structure of ferrite （Spinel）, the more the coatings. From the SEM micrograph, the particle size was increased from about 80 nm to about 120 nm.