A sol-gel method was used to prepare TiO_2 and sulfur-TiO_2(S-TiO_2) nanocomposites, which were characterized by N_2 adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescene, ultrav...A sol-gel method was used to prepare TiO_2 and sulfur-TiO_2(S-TiO_2) nanocomposites, which were characterized by N_2 adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescene, ultraviolet visible and transmission electron microscopy measurements. The photocatalytic performance of TiO_2 and S-TiO_2 nanocomposites, with respect to the photocatalytic oxidation of cyanide under visible light irradiation, was determined. The results reveal that S is well dispersed on the surface of TiO_2 nanoparticles. Additionally, the surface area of the S-TiO_2 nanocomposites was observed to be smaller than that of the TiO_2 nanoparticles because of blocked pores caused by doping with S. The S-TiO_2 nanocomposite(0.3 wt% S) exhibited the lowest band gap and the highest photocatalytic activity in the oxidation of cyanide. The photocatalytic performance of S-TiO_2(0.3 wt% S) nanocomposites was stable, even after the fifth reuse of the nanoparticles for the oxidation of cyanide.展开更多
The current work deals with ZnO-Ag nanocomposites（in the wide range of x in the Zn1-x O-Ag x chemical composition） synthesized using microwave assisted solution combustion method.The structural, morphological and op...The current work deals with ZnO-Ag nanocomposites（in the wide range of x in the Zn1-x O-Ag x chemical composition） synthesized using microwave assisted solution combustion method.The structural, morphological and optical properties of the samples were characterized by XRD（X-ray diffraction）, FTIR（Fourier transform infrared spectrometry）, SEM（scanning electron microscopy technique）, EDX（energy dispersive X-ray spectrum）, ICP（inductively coupled plasma technique）, TEM（transmission electron microscopy）, BET（Brunauer–Emmett–Teller method）, UV–Vis（ultraviolet–visible spectrophotometer） and photoluminescence spectrophotometer. The photocatalytic activity of the ZnO-Ag was investigated by photo-degradation of Acid Blue 113（AB 113） under UV illumination in a semi-batch reactor. This experiment showed that ZnO-Ag has much more excellent photocatalytic properties than ZnO synthesized by the same method. The enhanced photocatalytic activity was due to the decrease in recombination of photogenerated electron-holes. The results showed the improvement of ZnO photocatalytic activity and there is an optimum amount of Ag（3.5 mol%） that needs to be doped with ZnO.The effect of operating parameters such as p H, catalyst dose and dye concentration were investigated. The reaction byproducts were identified by LC/MS（liquid chromatography/mass spectrometry） analysis and a pathway was proposed as well. Kinetic studies indicated that the decolorization process follows the first order kinetics. Also, the degradation percentage of AB113 was determined using a total organic carbon（TOC） analyzer. Additionally, cost analysis of the process, the mechanism and the role of Ag were discussed.展开更多
文摘A sol-gel method was used to prepare TiO_2 and sulfur-TiO_2(S-TiO_2) nanocomposites, which were characterized by N_2 adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescene, ultraviolet visible and transmission electron microscopy measurements. The photocatalytic performance of TiO_2 and S-TiO_2 nanocomposites, with respect to the photocatalytic oxidation of cyanide under visible light irradiation, was determined. The results reveal that S is well dispersed on the surface of TiO_2 nanoparticles. Additionally, the surface area of the S-TiO_2 nanocomposites was observed to be smaller than that of the TiO_2 nanoparticles because of blocked pores caused by doping with S. The S-TiO_2 nanocomposite(0.3 wt% S) exhibited the lowest band gap and the highest photocatalytic activity in the oxidation of cyanide. The photocatalytic performance of S-TiO_2(0.3 wt% S) nanocomposites was stable, even after the fifth reuse of the nanoparticles for the oxidation of cyanide.
文摘The current work deals with ZnO-Ag nanocomposites（in the wide range of x in the Zn1-x O-Ag x chemical composition） synthesized using microwave assisted solution combustion method.The structural, morphological and optical properties of the samples were characterized by XRD（X-ray diffraction）, FTIR（Fourier transform infrared spectrometry）, SEM（scanning electron microscopy technique）, EDX（energy dispersive X-ray spectrum）, ICP（inductively coupled plasma technique）, TEM（transmission electron microscopy）, BET（Brunauer–Emmett–Teller method）, UV–Vis（ultraviolet–visible spectrophotometer） and photoluminescence spectrophotometer. The photocatalytic activity of the ZnO-Ag was investigated by photo-degradation of Acid Blue 113（AB 113） under UV illumination in a semi-batch reactor. This experiment showed that ZnO-Ag has much more excellent photocatalytic properties than ZnO synthesized by the same method. The enhanced photocatalytic activity was due to the decrease in recombination of photogenerated electron-holes. The results showed the improvement of ZnO photocatalytic activity and there is an optimum amount of Ag（3.5 mol%） that needs to be doped with ZnO.The effect of operating parameters such as p H, catalyst dose and dye concentration were investigated. The reaction byproducts were identified by LC/MS（liquid chromatography/mass spectrometry） analysis and a pathway was proposed as well. Kinetic studies indicated that the decolorization process follows the first order kinetics. Also, the degradation percentage of AB113 was determined using a total organic carbon（TOC） analyzer. Additionally, cost analysis of the process, the mechanism and the role of Ag were discussed.
