Mesoporous CeO2 nanowires(NWs) were synthesized through a facile hydrothermal process by using triblock copolymer F127 as the template.XRD analysis confirmed the cubic phase of the synthesized CeO2 NWs.High-yield one-...Mesoporous CeO2 nanowires(NWs) were synthesized through a facile hydrothermal process by using triblock copolymer F127 as the template.XRD analysis confirmed the cubic phase of the synthesized CeO2 NWs.High-yield one-dimensional NWs with accessible mesopores could be observed from SEM and TEM images,and the surface area of the material was confirmed to be 273 m2 g-1 with pore width distribution of 6.9-13.8 nm.The mesoporous CeO2 NWs could be used as efficient photocatalysts for organic dye degradation under UV light irradiation,which was superior compared with commercial photocatalyst P-25 and commercial CeO2 powders.The NW structure facilitates the recovery of catalyst by sedimentation,leading to the impressive reusability of these mesoporous CeO2 NWs.展开更多
Cobalt (Co) exists in significant quantities in naturally occurring manganese (Mn) oxides and alters the growth of Mn oxide crystals. Four-layered Mn oxides, Na-buserite (Na-bus) and three Co-doped Na-buserite s...Cobalt (Co) exists in significant quantities in naturally occurring manganese (Mn) oxides and alters the growth of Mn oxide crystals. Four-layered Mn oxides, Na-buserite (Na-bus) and three Co-doped Na-buserite samples prepared from oxidation of Mn(OH)2 with 5%, 10%, and 20% Co/(Mn + Co) molar ratios (5Co-Na-bus, 10Co-Na-bus, and 20Co-Na-bus), were used to prepare todorokite, a common Mn oxide on the Earth's surface, using Mg2+/Co2+ ions as a template. The results showed that todorokites could be obtained by reflux treatment of Mg2+-exchanged non-doped Na-buserite and three Co-doped Na-buserites at atmospheric pressure. However, the formation of todorokites was prohibited by reflux treatment of Co2+-exchanged Na-bus, 5Co-Na-bus, and 10Co-Na-bus samples. Instead, todorokite was obtained by the reflux treatment of Co2+-exchanged 20Co-Na-bus samples under atmospheric pressure. X-ray photoelectron spectroscopy analysis showed that doped Co existed as Co3+ in the MnOs layers of doped Na-buserites. The amount of substituted Co3+ in the MnO6 layers may play a key role in the conversion of buserite to todorokite using Co2+ ions as a template.展开更多
基金supported by the Engineering and Technology Research Center of Food Preservation,Processing and Safety Control of Liaoning Province,Food Safety Key Lab of Liaoning Province (LNSAKF2011027)Key Laboratory Project of Department of Education of LiaoningProvince (2009s004)
文摘Mesoporous CeO2 nanowires(NWs) were synthesized through a facile hydrothermal process by using triblock copolymer F127 as the template.XRD analysis confirmed the cubic phase of the synthesized CeO2 NWs.High-yield one-dimensional NWs with accessible mesopores could be observed from SEM and TEM images,and the surface area of the material was confirmed to be 273 m2 g-1 with pore width distribution of 6.9-13.8 nm.The mesoporous CeO2 NWs could be used as efficient photocatalysts for organic dye degradation under UV light irradiation,which was superior compared with commercial photocatalyst P-25 and commercial CeO2 powders.The NW structure facilitates the recovery of catalyst by sedimentation,leading to the impressive reusability of these mesoporous CeO2 NWs.
基金Supported by the National Natural Science Foundation of China(Nos.41001139 and 40771102)
文摘Cobalt (Co) exists in significant quantities in naturally occurring manganese (Mn) oxides and alters the growth of Mn oxide crystals. Four-layered Mn oxides, Na-buserite (Na-bus) and three Co-doped Na-buserite samples prepared from oxidation of Mn(OH)2 with 5%, 10%, and 20% Co/(Mn + Co) molar ratios (5Co-Na-bus, 10Co-Na-bus, and 20Co-Na-bus), were used to prepare todorokite, a common Mn oxide on the Earth's surface, using Mg2+/Co2+ ions as a template. The results showed that todorokites could be obtained by reflux treatment of Mg2+-exchanged non-doped Na-buserite and three Co-doped Na-buserites at atmospheric pressure. However, the formation of todorokites was prohibited by reflux treatment of Co2+-exchanged Na-bus, 5Co-Na-bus, and 10Co-Na-bus samples. Instead, todorokite was obtained by the reflux treatment of Co2+-exchanged 20Co-Na-bus samples under atmospheric pressure. X-ray photoelectron spectroscopy analysis showed that doped Co existed as Co3+ in the MnOs layers of doped Na-buserites. The amount of substituted Co3+ in the MnO6 layers may play a key role in the conversion of buserite to todorokite using Co2+ ions as a template.