Synthesis And Photocatalytic Properties Of Metal Or Nonmetal-doped ZnO/Ag Nanocomposites

In this paper, ZnO/Ag nanocomposites doped by Fe, Cd and N were prepared for improving photocatalytic properties of nanocomposites.1. Fe-doped ZnO/Ag nanocomposites were prepared by dual-step liquid deposition approach with ZnSO4, NH4HCO3, AgNO3, Fe2(SO4)3 as raw materials. The influences of iron-doped concentration and iron-doped ratio on photocatalytic properties of ZnO/Ag nanocomposites were systemically studied. The micromorphology, microstructures were characterized by transmission electron microcopy, X-ray diffraction. The photocatalytic properties of Fe doped-ZnO/Ag nanocomposites were analyzed quantitatively by UV-vis and macroscopic color change of methyl orange solutions.The results show that: doping iron could improve the photocatalytic properties of ZnO/Ag nanocomposites. Fe-doped ZnO/Ag nanocomposite was well-dispersed with small particle size between 15-20 nm. The photocatalytic properties of Fe-doped ZnO/Ag nanocomposites with doping concentration of 0.134 mol?L-1 and doping ratio of 5 % were best, and the degradation ratio of methyl orange solutions was 97.2 % after 3 h.2. Cd-doped ZnO/Ag nanocomposites were prepared by coordination homogeneous precipitation approach with Zn(NO3)2, (NH4)2CO3, AgNO3, Cd(NO3)2, NH3·H2O as raw materials. The influences of cadmium-doped concentration and cadmium-doped ratio on photocatalytic properties of ZnO/Ag nanocomposites were systemically studied. The micromorphology, microstructures, components, contents of components were characterized by transmission electron microcopy, X-ray diffraction, Fourier transform infrared spectroscopy and inductively coupled plasma emission spectrometer. The photocatalytic properties of Cd doped-ZnO/Ag nanocomposites were analyzed quantitatively by UV-vis and macroscopic color change of methyl orange solutions.The results show that: doping cadmium could improve the photocatalytic properties of ZnO/Ag nanocomposites. Cd-doped ZnO/Ag nanocomposite was well-dispersed with small particle size about 20 nm. The optimization cadmium-doping conditions are shown as follows: the reactant concentration 0.084 mol/L, the doping ratio 1:12, and the degradation ratio of methyl orange solutions was 97.9 % after 3 h. The mass rate of Cd, Zn and Ag of this Cd-doped ZnO/Ag nanocomposite is 5:33:3.3. N-doped ZnO/Ag nanocomposites were prepared by a combination of liquid deposition approach and subsequent plasma nitriding with Zn(SO4)2, NH4HCO3, AgNO3, N2, H2 as raw materials. The influences of nitriding time on photocatalytic properties of ZnO/Ag nanocomposites were systemically studied. The micromorphology, microstructures, contents of components were characterized by transmission electron microcopy, X-ray diffraction, elemental analyzer. The photocatalytic properties of N doped-ZnO/Ag nanocomposites were analyzed quantitatively by UV-vis and macroscopic color change of methyl orange solutions.The results show that: doping nitrogen could improve the photocatalytic properties of ZnO/Ag nanocomposites. N-doped ZnO/Ag nanocomposite was well-dispersed with small particle size between 15-20 nm. The photocatalytic properties of N-doped ZnO/Ag nanocomposites with nitriding time 30 min were best, and the degradation ratio of methyl orange solutions was 99.7 % after 2 h.4. N-doped ZnO/Ag nanocomposites were prepared by a combination of liquid deposition approach and atmosphere nitriding with Zn(SO4)2, NH4HCO3, AgNO3, C3N3H6 as raw materials. The influences of nitriding time, nitrogen-doped ratio, holding time on photocatalytic properties of ZnO/Ag nanocomposites were systemically studied. The micromorphology, microstructures, contents of components were characterized by transmission electron microcopy, X-ray diffraction, inductively coupled plasma emission spectrometer and elemental analyzer. The photocatalytic properties of N doped-ZnO/Ag nanocomposites were analyzed quantitatively by UV-vis and macroscopic color change of methyl orange solutions.The results show that: doping nitrogen could improve the photocatalytic properties of ZnO/Ag nanocomposites. N-doped ZnO/Ag nanocomposite was well-dispersed with small particle size between 15-20 nm. The nitriding time, nitrogen-doped ratio and holding time affected the photocatalytic properties of ZnO/Ag nanocomposites, and the maximum impact factor was doping ratio. When nitriding parameter was 380℃, 1, 2.5 h, the degradation rate of methyl orange was the best and was 94 % after 30 min, and N wt. % was 2.564 %.