Synthesis, Characterization And Its Photocatalytic Degradation Using Cd2+-doped And Cd2+-al3+ Co-doped Zno

Nanometer material is known as the 21 most promising materials", particularly nanometer ZnO possesses special properties such as superficial effect and volumetric effect. It is widely used in the industries of pottery, coating, rubber and so on and can also be used as the materials in the photocatalyst, conduction, magnetism etc. The energy gap of bulk material ZnO is 3.2 eV, corresponding to the ultraviolet light of the wavelength 387 nm. As a kind of important photocatalyst, semiconductor material-ZnO has been widely studied in recent years. It is difficult to be applied in engineering due to the lower photocatalytic efficiency of pure ZnO, which however can be improved by compounding semiconductors or doping, therefore it has become the subject of increasing attention in the scientific field.In this paper, pure ZnO , Cd²⁺-doped ZnO and Cd²⁺-Al³⁺ co-doped ZnO were prepared using sol–gel method with zinc acetate dehydrate [Zn(CH₃COO)₂·2H₂O], lithium hydroxide monohydrate (LiOH·H₂O), cadmium chloride (CdCl₂·2.5H₂O), aluminum chloride (AlCl₃·6H₂O) as raw material. The samples were characterized by means of X-ray diffraction (XRD), infrared absorption spectroscopy (IR), UV-Vis spectroscopy and high resolution transmission electron microscope(HR-TEM). The photocatalytic performance of different ZnO samples were studied using ultraviolet lamp as illumination device and reactive brilliant blue X-BR as stimulant pollutant. The relationship between the amount of Al³⁺ doping or Cd²⁺-Al²⁺-codoping with degradation rate was also discussed.The results indicated that the doping was well-proportioned doped into ZnO sample.Moreover Cd²⁺ dopants or Al³⁺-Cd²⁺ co-doping in ZnO increased the uniformity of the particles and make the particle remarkably smaller so that they are efficient to improve the photocatalytic performance of ZnO. In particular, among the samples of single dopant, 0.5%Cd²⁺-doped particle ,has the best photocatalytic performance and sa dose 0.2%Cd²⁺-4.5%Al³⁺ co-doped ZnO particle in the co-doped samples. We also found a quantitative result that when the reaction temperature was 30℃, the degradation rate of reactive brilliant blue X-BR could reach 76.49% by catalyst of 0.1 g/L in 60 min.