Corn rod-like WO<sub>3</sub> nanomaterials were successfully synthesized by a simple hydrothermal method. The morphology, structure and optical absorption properties of the prepared samples were characteri...Corn rod-like WO<sub>3</sub> nanomaterials were successfully synthesized by a simple hydrothermal method. The morphology, structure and optical absorption properties of the prepared samples were characterized by SEM, XRD, FTIR and UV-Vis-DRS. The WO<sub>3</sub> materials were corn rod-like morphology with about 800 nm for length and 150 nm for diameter, especially there were plenty of corn particles (about 20 nm) on the surface of corn rods. The X-ray diffraction peaks of the products corresponded with WO<sub>3</sub> standard card, and the characteristic peak of W-O bond was found in the infrared spectrum. The absorption band edge of the products was about 480 nm, indicating their potential visible-light-induced photocatalytic activity. In situ FTIR technology research showed that the prepared WO<sub>3</sub> nanomaterials had visible photocatalytic activity to gas-phase toluene. After a photocatalytic reaction for 8 hours toluene was effectively degraded, and carboxylic acid and aldehyde could be regarded as the intermediate products, and CO<sub>2</sub> was produced as the final product during the reaction process.展开更多
High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of...High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ～1.4 mol ? L^(-1) and0.031～0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ～18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .展开更多
Yb 3+-doped TiO_2 composite nano-particles were prepared by the acid-catalyzed sol-gel method using Ti(OC_4H_9)_4 and Yb(NO_3)_3 as precursors. The effects of the amount of Yb 3+ doping and calcination temperature on ...Yb 3+-doped TiO_2 composite nano-particles were prepared by the acid-catalyzed sol-gel method using Ti(OC_4H_9)_4 and Yb(NO_3)_3 as precursors. The effects of the amount of Yb 3+ doping and calcination temperature on the phase transformation, crystallite size, surface texture of the nanopowders were investigated by XRD and BET specific surface area. Their photocatalytic activities were evaluated using the photocatalytic degradation of methylene blue in aqueous solution as a probe reaction. At the interface, titanium ions substitute for ytterbium ions in the lattice of Yb_2O_3 to form Ti-O-Yb bonds, which cause distortion and inhibit the anatase to rutile phase transformation in TiO_2. The results indicate that Yb 3+-doping can enhance the photocatalytic activity of TiO_2 nano-powders as compared with pure TiO_2. 0.125%(mass fraction) Yb 3+ doped TiO_2 nano-powders calcined at 600 ℃ for 2 h show the highest photocatalytic activity. The increase in photoactivity is due to the effects of the factors such as crystal phase, crystallite size, surface chemical property, surface density of OH groups, and surface texture properties of the TiO_2 nano-powders.展开更多
文摘Corn rod-like WO<sub>3</sub> nanomaterials were successfully synthesized by a simple hydrothermal method. The morphology, structure and optical absorption properties of the prepared samples were characterized by SEM, XRD, FTIR and UV-Vis-DRS. The WO<sub>3</sub> materials were corn rod-like morphology with about 800 nm for length and 150 nm for diameter, especially there were plenty of corn particles (about 20 nm) on the surface of corn rods. The X-ray diffraction peaks of the products corresponded with WO<sub>3</sub> standard card, and the characteristic peak of W-O bond was found in the infrared spectrum. The absorption band edge of the products was about 480 nm, indicating their potential visible-light-induced photocatalytic activity. In situ FTIR technology research showed that the prepared WO<sub>3</sub> nanomaterials had visible photocatalytic activity to gas-phase toluene. After a photocatalytic reaction for 8 hours toluene was effectively degraded, and carboxylic acid and aldehyde could be regarded as the intermediate products, and CO<sub>2</sub> was produced as the final product during the reaction process.
文摘High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ～1.4 mol ? L^(-1) and0.031～0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ～18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .
文摘Yb 3+-doped TiO_2 composite nano-particles were prepared by the acid-catalyzed sol-gel method using Ti(OC_4H_9)_4 and Yb(NO_3)_3 as precursors. The effects of the amount of Yb 3+ doping and calcination temperature on the phase transformation, crystallite size, surface texture of the nanopowders were investigated by XRD and BET specific surface area. Their photocatalytic activities were evaluated using the photocatalytic degradation of methylene blue in aqueous solution as a probe reaction. At the interface, titanium ions substitute for ytterbium ions in the lattice of Yb_2O_3 to form Ti-O-Yb bonds, which cause distortion and inhibit the anatase to rutile phase transformation in TiO_2. The results indicate that Yb 3+-doping can enhance the photocatalytic activity of TiO_2 nano-powders as compared with pure TiO_2. 0.125%(mass fraction) Yb 3+ doped TiO_2 nano-powders calcined at 600 ℃ for 2 h show the highest photocatalytic activity. The increase in photoactivity is due to the effects of the factors such as crystal phase, crystallite size, surface chemical property, surface density of OH groups, and surface texture properties of the TiO_2 nano-powders.
