Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-...Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.展开更多
Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked ...Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked with γ-HCH, soil samples were loaded with α-Fe 2O 3 or TiO 2 and exposed to UV-light irradiation. Different catalyst loads, 0%, 2%, 5%, 7%, and 10% (wt.)α-Fe 2O 3; 0%, 0.5%, 1%, 2:(wt.)TiO 2, were tested for up to 7 d irradiation. The effects of soil thickness, acidity, and humic substances were also investigated. The obtained results indicated that the γ-HCH photodegradation follows the pseudo-first-order kinetics. The addition of α-Fe 2O 3 or TiO 2 accelerates the photodegradation of γ-HCH, while the photodegradation rate decreases when the content of α-Fe 2O 3 exceeds 7%(wt.). The degradation rate increases with the soil pH value. Humic substances inhibit the photocatalytic degradation of γ-HCH. Pentachlorocyclohexene, tetrachlorocyclohexene, and trichlorobenzene are detected as photodegradation intermediates, which are gradually degraded with the photodegradation evolution.展开更多
A complex additive has been synthesized from maleic acid, sodium hypophosphite and Zn 2+ dodecyl-polyglucoside. It was used to prepare α-FeOOH by alkaline method with different concentration of additive oxidation of ...A complex additive has been synthesized from maleic acid, sodium hypophosphite and Zn 2+ dodecyl-polyglucoside. It was used to prepare α-FeOOH by alkaline method with different concentration of additive oxidation of Fe 2+ has been discussed. The result showed that particle pattern of α-FeOOH was better when additive concentration was 1 0×10 -3 g/L. The γ-Fe 2O 3 powder with perfect comprehensive quality was prepared from α-FeOOH by dehydration, roast, reduction and oxidation.展开更多
CO adsorption microcalorimetry was employed in the study of γ-Al-2O-3-supported Pt, Pt-Sn and Pt-Fe catalysts. The results indicated that the initial differential heat of CO adsorption of the Pt/γ-Al-2O-3 catalyst w...CO adsorption microcalorimetry was employed in the study of γ-Al-2O-3-supported Pt, Pt-Sn and Pt-Fe catalysts. The results indicated that the initial differential heat of CO adsorption of the Pt/γ-Al-2O-3 catalyst was 125 kJ/mol. As CO coverage increased, the differential heat of adsorption decreased. At higher coverages, the differential heat of adsorption decreased significantly. 60% of the differential heat of CO adsorption on the Pt/γ-Al-2O-3 catalyst was higher than 100 kJ/mol. No significant effect on the initial differential heat was found after adding Sn and Fe to the Pt/γ-Al-2O-3 catalyst. The amount of strong CO adsorption sites decreased, while the portion of CO adsorption sites with differential heat of 60110 kJ/mol increased after increasing the Sn or Fe content. This indicates that the surface adsorption energy was changed by adding Sn or Fe to Pt/γ-Al-2O-3. The distribution of differential heat of CO adsorption on the Pt-Sn（C）/γ-Al-2O-3 catalyst was broad and homogeneous. Comparison of the dehydrogenation performance of C-4 alkanes with the number of CO adsorption sites with differential heat of 60110 kJ/mol showed a good correlation. These results indicate that the surface Pt centers with differential heats of 60110 kJ/mol for CO adsorption possess superior activity for the dehydrogenation of alkanes.展开更多
文摘Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.
文摘Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked with γ-HCH, soil samples were loaded with α-Fe 2O 3 or TiO 2 and exposed to UV-light irradiation. Different catalyst loads, 0%, 2%, 5%, 7%, and 10% (wt.)α-Fe 2O 3; 0%, 0.5%, 1%, 2:(wt.)TiO 2, were tested for up to 7 d irradiation. The effects of soil thickness, acidity, and humic substances were also investigated. The obtained results indicated that the γ-HCH photodegradation follows the pseudo-first-order kinetics. The addition of α-Fe 2O 3 or TiO 2 accelerates the photodegradation of γ-HCH, while the photodegradation rate decreases when the content of α-Fe 2O 3 exceeds 7%(wt.). The degradation rate increases with the soil pH value. Humic substances inhibit the photocatalytic degradation of γ-HCH. Pentachlorocyclohexene, tetrachlorocyclohexene, and trichlorobenzene are detected as photodegradation intermediates, which are gradually degraded with the photodegradation evolution.
文摘A complex additive has been synthesized from maleic acid, sodium hypophosphite and Zn 2+ dodecyl-polyglucoside. It was used to prepare α-FeOOH by alkaline method with different concentration of additive oxidation of Fe 2+ has been discussed. The result showed that particle pattern of α-FeOOH was better when additive concentration was 1 0×10 -3 g/L. The γ-Fe 2O 3 powder with perfect comprehensive quality was prepared from α-FeOOH by dehydration, roast, reduction and oxidation.
文摘CO adsorption microcalorimetry was employed in the study of γ-Al-2O-3-supported Pt, Pt-Sn and Pt-Fe catalysts. The results indicated that the initial differential heat of CO adsorption of the Pt/γ-Al-2O-3 catalyst was 125 kJ/mol. As CO coverage increased, the differential heat of adsorption decreased. At higher coverages, the differential heat of adsorption decreased significantly. 60% of the differential heat of CO adsorption on the Pt/γ-Al-2O-3 catalyst was higher than 100 kJ/mol. No significant effect on the initial differential heat was found after adding Sn and Fe to the Pt/γ-Al-2O-3 catalyst. The amount of strong CO adsorption sites decreased, while the portion of CO adsorption sites with differential heat of 60110 kJ/mol increased after increasing the Sn or Fe content. This indicates that the surface adsorption energy was changed by adding Sn or Fe to Pt/γ-Al-2O-3. The distribution of differential heat of CO adsorption on the Pt-Sn（C）/γ-Al-2O-3 catalyst was broad and homogeneous. Comparison of the dehydrogenation performance of C-4 alkanes with the number of CO adsorption sites with differential heat of 60110 kJ/mol showed a good correlation. These results indicate that the surface Pt centers with differential heats of 60110 kJ/mol for CO adsorption possess superior activity for the dehydrogenation of alkanes.
