Graphite-like C3N4 （g-C3N4） is an efficient visible-light-driven photocatalyst which is com- monly used in pollutant degradation. The photoreactivity of g-C3N4 depends on the prepa- ration conditions to a large exte...Graphite-like C3N4 （g-C3N4） is an efficient visible-light-driven photocatalyst which is com- monly used in pollutant degradation. The photoreactivity of g-C3N4 depends on the prepa- ration conditions to a large extent. In this work, we linked the preparation conditions of g-C3N4 to its stability and photocatalytic activity through dye photodegradation experiments and sensitivity mathematical analyses. The sensitivity mathematical analyses show that the effect of calcination temperature is more significant than calcination time on the photoreactivity of g-C3N4. The photocatalytic activity of optimized g-C3N4 in rhodamine B （RhB） degradation under visible light was 100 times higher than that of non-optimized one. The enhanced performance can be attributed to the increased specific surface area of g-C3N4 and the increased migration velocity of photogenerated electron-hole pairs on the surface. This work deepens the understanding of the relation between preparation conditions and the charateristics of g-C3N4, and provides an extremely simple method for significantly improving the photoreactivity of g-C3N4.展开更多
Preparation method of photocatalyst, using TiCl4 and SnCl2 as raw material and photocatalytic activity of nano-scaled core-shell Sn^2＋ -doped titania photocatalyst was studied in this paper. The as-prepared samples w...Preparation method of photocatalyst, using TiCl4 and SnCl2 as raw material and photocatalytic activity of nano-scaled core-shell Sn^2＋ -doped titania photocatalyst was studied in this paper. The as-prepared samples were studied by UV-Vis, XRD, XPS, TEM. The particles of Sn^2＋-doped TiO2 photocatalyst, calcined from 150 to 600 ℃ for 5 h, possesses narrow particle size distribution and the sample was composed of anatase phase. Its photocatalytic efficiency was investigated by UV irradiation.展开更多
Monoclinic BiVO4 hollow nanospheres were successfully prepared via template-free method using citric acid （C6H8O7） as chelating agent and characterized by X-ray diffraction patterns, transmission electron microscope...Monoclinic BiVO4 hollow nanospheres were successfully prepared via template-free method using citric acid （C6H8O7） as chelating agent and characterized by X-ray diffraction patterns, transmission electron microscope, UV-Vis DRS, and TG-DTA technique. C6H8O7 played an important role in the formation of hollow spheres. Morphology observations revealed that when appropriate amount of C6H8O7 was introduced, the cavity with the diameter of 40 nm was obtained in BiVO4 nanospheres. UV-Vis diffuse reflectance spectra indicated that the samples had absorption in both UV and visible light region. The photocatalytic activities were evaluated by the degradation of methylene blue under Xe lamp irradiation. Hollow spheres endow BiVO4 samples with greatly improved photocatalytic activity. A possible formation mechanism of hollow spheres was proposed.展开更多
N-doped TiO2 nanoparticle photocatalysts were prepared through a sol-gel procedure using NH4C1 as the nitrogen source and followed by calcination at certain temperature. Systematic studies for the preparation paramete...N-doped TiO2 nanoparticle photocatalysts were prepared through a sol-gel procedure using NH4C1 as the nitrogen source and followed by calcination at certain temperature. Systematic studies for the preparation parameters and their impact on the structure and photocatalytic activity under ultraviolet （UV） and visible light irra-diation were carried out. Multiple techniques （XRD, TEM, DRIF, DSC, and XPS） were commanded to characterize the crystal structures and chemical binding of N-doped TiO2. Its photocatalytic activity was examined by the deg- radation of organic compounds. The catalytic activity of the prepared N-doped TiO2 nanoparticles under visible light （λ〉400nm） irradiation is evidenced by the decomposition of 4-chlorophenol, showing that nitrogen atoms in the N-doped TiO2 nanoparticle catalyst are responsible for the visible light catalytic activity. The N-doped TiO2 nanoparticle catalyst prepared with this modified route exhibits higher catalytic activity under UV irradiation in contrast to TiO2 without N-doping. It is suggested that the doped nitrogen here is located at the interstitial site of TiO2 lattice.展开更多
Nano zinc oxide(ZnO)has excellent performance and low cost,but ZnO has a wide band gap and its electron-hole is difficult to achieve effective separation,which greatly limits its photocatalytic activity.This paper int...Nano zinc oxide(ZnO)has excellent performance and low cost,but ZnO has a wide band gap and its electron-hole is difficult to achieve effective separation,which greatly limits its photocatalytic activity.This paper introduces the structural properties of ZnO and the mechanism of photocatalytic degradation of organic pollutants,and summarizes the preparation of ZnO nanomaterials and the application studies in improving its photocatalytic properties,in order to promote the research and development of ZnO nanomaterials.展开更多
文摘Graphite-like C3N4 （g-C3N4） is an efficient visible-light-driven photocatalyst which is com- monly used in pollutant degradation. The photoreactivity of g-C3N4 depends on the prepa- ration conditions to a large extent. In this work, we linked the preparation conditions of g-C3N4 to its stability and photocatalytic activity through dye photodegradation experiments and sensitivity mathematical analyses. The sensitivity mathematical analyses show that the effect of calcination temperature is more significant than calcination time on the photoreactivity of g-C3N4. The photocatalytic activity of optimized g-C3N4 in rhodamine B （RhB） degradation under visible light was 100 times higher than that of non-optimized one. The enhanced performance can be attributed to the increased specific surface area of g-C3N4 and the increased migration velocity of photogenerated electron-hole pairs on the surface. This work deepens the understanding of the relation between preparation conditions and the charateristics of g-C3N4, and provides an extremely simple method for significantly improving the photoreactivity of g-C3N4.
基金The National Natural Science Foundation of China(No.20271007 and 20331010)Specialized Research Fund for the Doctoral Program of Higher Education(No.20030007014)are acknowledged for financial support.
文摘Preparation method of photocatalyst, using TiCl4 and SnCl2 as raw material and photocatalytic activity of nano-scaled core-shell Sn^2＋ -doped titania photocatalyst was studied in this paper. The as-prepared samples were studied by UV-Vis, XRD, XPS, TEM. The particles of Sn^2＋-doped TiO2 photocatalyst, calcined from 150 to 600 ℃ for 5 h, possesses narrow particle size distribution and the sample was composed of anatase phase. Its photocatalytic efficiency was investigated by UV irradiation.
文摘Monoclinic BiVO4 hollow nanospheres were successfully prepared via template-free method using citric acid （C6H8O7） as chelating agent and characterized by X-ray diffraction patterns, transmission electron microscope, UV-Vis DRS, and TG-DTA technique. C6H8O7 played an important role in the formation of hollow spheres. Morphology observations revealed that when appropriate amount of C6H8O7 was introduced, the cavity with the diameter of 40 nm was obtained in BiVO4 nanospheres. UV-Vis diffuse reflectance spectra indicated that the samples had absorption in both UV and visible light region. The photocatalytic activities were evaluated by the degradation of methylene blue under Xe lamp irradiation. Hollow spheres endow BiVO4 samples with greatly improved photocatalytic activity. A possible formation mechanism of hollow spheres was proposed.
基金Supported by the Science and Technology Research Program of Chongqing Education Commission （KJ050702）, and the Natural Science Foundation Project of Chongqing Science and Technology（Commission （No.2007BB7208）.
文摘N-doped TiO2 nanoparticle photocatalysts were prepared through a sol-gel procedure using NH4C1 as the nitrogen source and followed by calcination at certain temperature. Systematic studies for the preparation parameters and their impact on the structure and photocatalytic activity under ultraviolet （UV） and visible light irra-diation were carried out. Multiple techniques （XRD, TEM, DRIF, DSC, and XPS） were commanded to characterize the crystal structures and chemical binding of N-doped TiO2. Its photocatalytic activity was examined by the deg- radation of organic compounds. The catalytic activity of the prepared N-doped TiO2 nanoparticles under visible light （λ〉400nm） irradiation is evidenced by the decomposition of 4-chlorophenol, showing that nitrogen atoms in the N-doped TiO2 nanoparticle catalyst are responsible for the visible light catalytic activity. The N-doped TiO2 nanoparticle catalyst prepared with this modified route exhibits higher catalytic activity under UV irradiation in contrast to TiO2 without N-doping. It is suggested that the doped nitrogen here is located at the interstitial site of TiO2 lattice.
基金National Natural Science Foundation of China(No.11672198)。
文摘Nano zinc oxide(ZnO)has excellent performance and low cost,but ZnO has a wide band gap and its electron-hole is difficult to achieve effective separation,which greatly limits its photocatalytic activity.This paper introduces the structural properties of ZnO and the mechanism of photocatalytic degradation of organic pollutants,and summarizes the preparation of ZnO nanomaterials and the application studies in improving its photocatalytic properties,in order to promote the research and development of ZnO nanomaterials.
