Neodymium doping titania was loaded to silicon dioxide to prepare Nd/TiO2-SiO2 by sol-gel method and Nd/TiO2-SiO2 was characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transf...Neodymium doping titania was loaded to silicon dioxide to prepare Nd/TiO2-SiO2 by sol-gel method and Nd/TiO2-SiO2 was characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform-infrared spectroscopy （FT-IR） and diffuse reflectance spectra （DRS）. Photocatalytic activities of Nd/TiO2-SiO2 with different neodymium contents were evaluated by degradation of methyl orange. The light absorption of Nd/TiO2-SiO2 increased with increasing doping neodymium in a visible light range of 388-619 nm, and Nd doping was in favor of decreasing the recombination of photo-generated electrons with holes. Nd and SiO2 improved the photocatalytic activity of TiO2. The optimal molar fraction of Nd to Ti was 0.1%, and the optimum calcination temperature was 600 ℃. The highest degradation rate of methyl orange was 82.9% after irradiation for 1 h.展开更多
Nd ： YAG precursor powders were synthesized by homogeneous precipitation, and Nd ： YAG transparent ceramics were prepared by vacuum sintering at 1700 ℃ for 5 h. The ceramic materials were characterized by light tra...Nd ： YAG precursor powders were synthesized by homogeneous precipitation, and Nd ： YAG transparent ceramics were prepared by vacuum sintering at 1700 ℃ for 5 h. The ceramic materials were characterized by light transmittance and field emission gun-environment scanning microscope. Using statistics and stereology theory, study was carried out on the quantitative relationships between light transmittance and stereological parameters in three-dimensional Euclidean space. It is found that the transmittance of Nd：YAG with 1 mm in thickness is about 45% and 58% in visible and near-infrared wavelength, respectively. The transmittance linearly increases with increasing equivalent sphere diameter and reaches the theoretical value of single crystal when the equivalent sphere diameter is 20μm. The transmittance decreases with the increasing of mean specific area per unit volume of grain and discrete grains, and the transmittance decreases with increasing mean free distance of grains in Nd：YAG ceramics.展开更多
Nd∶NBW laser crystal with the size of Φ8 mm×20 mm was grown by the process of lifting and pulling. The growth technological parameters which have influence on the completeness of crystal were analyzed and the r...Nd∶NBW laser crystal with the size of Φ8 mm×20 mm was grown by the process of lifting and pulling. The growth technological parameters which have influence on the completeness of crystal were analyzed and the reasonable technological parameters were ascertained.展开更多
基金Project(2009B010100001) supported by the Key Academic Program of the 3rd Phase "211 Project" of South China Agricultural University, ChinaProject(2007B030103019) supported by Guangdong Science and Technology Development Foundation, China
文摘Neodymium doping titania was loaded to silicon dioxide to prepare Nd/TiO2-SiO2 by sol-gel method and Nd/TiO2-SiO2 was characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform-infrared spectroscopy （FT-IR） and diffuse reflectance spectra （DRS）. Photocatalytic activities of Nd/TiO2-SiO2 with different neodymium contents were evaluated by degradation of methyl orange. The light absorption of Nd/TiO2-SiO2 increased with increasing doping neodymium in a visible light range of 388-619 nm, and Nd doping was in favor of decreasing the recombination of photo-generated electrons with holes. Nd and SiO2 improved the photocatalytic activity of TiO2. The optimal molar fraction of Nd to Ti was 0.1%, and the optimum calcination temperature was 600 ℃. The highest degradation rate of methyl orange was 82.9% after irradiation for 1 h.
基金Project supported by Key Science and Technology of Chinese Ministry of Education (205037)
文摘Nd ： YAG precursor powders were synthesized by homogeneous precipitation, and Nd ： YAG transparent ceramics were prepared by vacuum sintering at 1700 ℃ for 5 h. The ceramic materials were characterized by light transmittance and field emission gun-environment scanning microscope. Using statistics and stereology theory, study was carried out on the quantitative relationships between light transmittance and stereological parameters in three-dimensional Euclidean space. It is found that the transmittance of Nd：YAG with 1 mm in thickness is about 45% and 58% in visible and near-infrared wavelength, respectively. The transmittance linearly increases with increasing equivalent sphere diameter and reaches the theoretical value of single crystal when the equivalent sphere diameter is 20μm. The transmittance decreases with the increasing of mean specific area per unit volume of grain and discrete grains, and the transmittance decreases with increasing mean free distance of grains in Nd：YAG ceramics.
文摘Nd∶NBW laser crystal with the size of Φ8 mm×20 mm was grown by the process of lifting and pulling. The growth technological parameters which have influence on the completeness of crystal were analyzed and the reasonable technological parameters were ascertained.
