Three PMoV heteropoly acids(HPAs)with different number of V atoms were synthesized and characterized by ICPAES,TG,IR and XRD.The IR spectra indicated that they are Keggin structure.Compared the IR spectrum of P...Three PMoV heteropoly acids(HPAs)with different number of V atoms were synthesized and characterized by ICPAES,TG,IR and XRD.The IR spectra indicated that they are Keggin structure.Compared the IR spectrum of PMo HPA with those of PMoV HPAs,it was found that the characteristic absorption peak values(CAPV)of all of the PMoV HPAS were redshifted.展开更多
Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at tempe...Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at temperatures between 450℃ and 900℃ in N_2 artmosphere. Then, in a successive activation stage, the product carbonized at 600℃ was activated in steam at 450-900℃ for 30 min, and at 600℃ for 5-30 min. The other carbonization products were activated at 600 and 900℃ for 30 min respectively. The products activated at 900℃ were then activated at 450℃ for 30 min again. The starting materiah carbonized products and all activation products were examined by FT-IR spectroscopy and some products were examined by X-ray photoelectron spectroscope (XPS). And the yields of the carbonized and activated products were calculated. By analysing these spectra, the amount of oxygen-containing functional groups of the activated products attained under various activation time, various activation temperature and various previous carbonization temperature was determined.展开更多
A series of Mo-doped ZnO photocatalysts with different Mo-dopant concentrations have been prepared by a grind- ing-calcination method. The structure of these photocatalysts was characterized by a variety of methods, i...A series of Mo-doped ZnO photocatalysts with different Mo-dopant concentrations have been prepared by a grind- ing-calcination method. The structure of these photocatalysts was characterized by a variety of methods, including N2 physical adsorption, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared （FT-IR） spectroscopy, photoluminescence （PL） emission spectroscopy, and UV-vis diffuse reflectance spectroscopy （DRS）. It was found that Mo6＋ could enter into the crystal lattice of ZnO due to the radius of MO6＋ （0.065 nm） being smaller than that of Zn2＋ （0.083 nm）. XRD results indicated that Mo6＋ suppressed the growth of ZnO crystals. The FT-IR spectroscopy results showed that the ZnO with 2 wt.% Mo-doping has a higher level of surface hydroxyl groups than pure ZnO. PL spectroscopy indicated that ZnO with 2 wt.% Mo-doping also exhibited the largest reduction in the intensity of the emission peak at 390 nm caused by the recombi- nation of photogenerated hole-electron pairs. The activities of the Mo-doped ZnO photocatalysts were investigated in the pho- tocatalytic degradation of acid orange II under UV light （2 = 365 nm） irradiation. It was found that ZnO with 2 wt.% Mo-doping showed much higher photocatalytic activity and stability than pure ZnO. The high photocatalytic performance of the Mo-doped ZnO can be attributed to a great improvement in the surface properties of ZnO, higher crystallinity and lower recombination rate of photogenerated hole-electron （e-/h＋） pairs. Moreover, the undoped Mo species may exist in the form of MoO3 and form MoO3/ZnO heterojunctions which further favors the separation of e/h＋ pairs.展开更多
In order to further separate the concentrate containing galena and jamesonite before undergoing hydrometallurgical process, flotation experiment was performed on the basis of mineralogical analysis.And the adsorption ...In order to further separate the concentrate containing galena and jamesonite before undergoing hydrometallurgical process, flotation experiment was performed on the basis of mineralogical analysis.And the adsorption mechanisms of collector H on galena and jamesonite were also studied by FT-IR spectra analysis and molecular dynamics(MD) simulation. The flotation result shows that the efficient separation can be achieved with H as selective collector. Galena concentrated with Pb grade of 72.09%and Pb recovery of 50.96% was obtained, and jamesonite concentrated with Sb grade and recovery of10.89% and 76.67% respectively was obtained as well. Infrared spectrum analysis indicates that collector H can adsorb on the surface of galena and react with Pb2+to generate hydrophobic salt, while no evident adsorption phenomenon was observed on the surface of jamesonite. The MD simulation and calculation results demonstrate that adsorption energy of collector H on galena and jamesonite surface is à872.74 k J/mol and à500.538 k J/mol, respectively, which means collector H is easier to adsorb on the surface of galena than that of jamesonite.展开更多
文摘Three PMoV heteropoly acids(HPAs)with different number of V atoms were synthesized and characterized by ICPAES,TG,IR and XRD.The IR spectra indicated that they are Keggin structure.Compared the IR spectrum of PMo HPA with those of PMoV HPAs,it was found that the characteristic absorption peak values(CAPV)of all of the PMoV HPAS were redshifted.
文摘Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at temperatures between 450℃ and 900℃ in N_2 artmosphere. Then, in a successive activation stage, the product carbonized at 600℃ was activated in steam at 450-900℃ for 30 min, and at 600℃ for 5-30 min. The other carbonization products were activated at 600 and 900℃ for 30 min respectively. The products activated at 900℃ were then activated at 450℃ for 30 min again. The starting materiah carbonized products and all activation products were examined by FT-IR spectroscopy and some products were examined by X-ray photoelectron spectroscope (XPS). And the yields of the carbonized and activated products were calculated. By analysing these spectra, the amount of oxygen-containing functional groups of the activated products attained under various activation time, various activation temperature and various previous carbonization temperature was determined.
基金supported by the National Natural Science Foundation ofChina (21067004)the Natural Science Foundation of Jiangxi Province,China (2010GZH0048)Jiangxi Province Educatien Department of Science and Technology Project (GJJ 12344)
文摘A series of Mo-doped ZnO photocatalysts with different Mo-dopant concentrations have been prepared by a grind- ing-calcination method. The structure of these photocatalysts was characterized by a variety of methods, including N2 physical adsorption, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared （FT-IR） spectroscopy, photoluminescence （PL） emission spectroscopy, and UV-vis diffuse reflectance spectroscopy （DRS）. It was found that Mo6＋ could enter into the crystal lattice of ZnO due to the radius of MO6＋ （0.065 nm） being smaller than that of Zn2＋ （0.083 nm）. XRD results indicated that Mo6＋ suppressed the growth of ZnO crystals. The FT-IR spectroscopy results showed that the ZnO with 2 wt.% Mo-doping has a higher level of surface hydroxyl groups than pure ZnO. PL spectroscopy indicated that ZnO with 2 wt.% Mo-doping also exhibited the largest reduction in the intensity of the emission peak at 390 nm caused by the recombi- nation of photogenerated hole-electron pairs. The activities of the Mo-doped ZnO photocatalysts were investigated in the pho- tocatalytic degradation of acid orange II under UV light （2 = 365 nm） irradiation. It was found that ZnO with 2 wt.% Mo-doping showed much higher photocatalytic activity and stability than pure ZnO. The high photocatalytic performance of the Mo-doped ZnO can be attributed to a great improvement in the surface properties of ZnO, higher crystallinity and lower recombination rate of photogenerated hole-electron （e-/h＋） pairs. Moreover, the undoped Mo species may exist in the form of MoO3 and form MoO3/ZnO heterojunctions which further favors the separation of e/h＋ pairs.
基金financially supported by the National Natural Science Foundation (Nos. 51104179 and 51374247)
文摘In order to further separate the concentrate containing galena and jamesonite before undergoing hydrometallurgical process, flotation experiment was performed on the basis of mineralogical analysis.And the adsorption mechanisms of collector H on galena and jamesonite were also studied by FT-IR spectra analysis and molecular dynamics(MD) simulation. The flotation result shows that the efficient separation can be achieved with H as selective collector. Galena concentrated with Pb grade of 72.09%and Pb recovery of 50.96% was obtained, and jamesonite concentrated with Sb grade and recovery of10.89% and 76.67% respectively was obtained as well. Infrared spectrum analysis indicates that collector H can adsorb on the surface of galena and react with Pb2+to generate hydrophobic salt, while no evident adsorption phenomenon was observed on the surface of jamesonite. The MD simulation and calculation results demonstrate that adsorption energy of collector H on galena and jamesonite surface is à872.74 k J/mol and à500.538 k J/mol, respectively, which means collector H is easier to adsorb on the surface of galena than that of jamesonite.
