In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic p...In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic properties and the optical response range of the natase nanocrystalline were analyzed and studied with the hybrid orbital theory. The results show that the band gap of the doped TiO2 was narrow, and the photocatalytic ability could be excited by the visible lighL and the doping of non metallic elements broadens the application range of TiO2, so that it could be excited under the visible light and obtained better use value.展开更多
The facet-dependent photocatalytic performance of TiO_2 nanocrystals has been extensively investigated due to their promising applications in renewable energy and environmental fields. However, the intrinsic distincti...The facet-dependent photocatalytic performance of TiO_2 nanocrystals has been extensively investigated due to their promising applications in renewable energy and environmental fields. However, the intrinsic distinction in the photocatalytic oxidation activities between the {001}and {101} facets of anatase TiO_2 nanocrystals is still unclear and under debate. In this work, a simple photoelectrochemical method was employed to meaningfully quantify the intrinsic photocatalytic activities of {001} and{101} faceted TiO_2 nanocrystal photoanodes. The effective surface areas of photoanodes with different facets were measured based on the monolayer adsorption of phthalic acid on TiO_2 photoanode surface by an ex situ photoelectrochemical method, which were used to normalize the photocurrents obtained from different faceted photoanodes for meaningful comparison of their photocatalytic activities. The results demonstrated that the {001} facets of anatase TiO_2 nanocrystals exhibited much better photocatalytic activity than that of {101} facets of anatase TiO_2 nanocrystals toward photocatalytic oxidation of water and organic compounds with different functional groups(e.g.,–OH, –CHO, –COOH). Furthermore, the instantaneous kinetic constants of photocatalytic oxidation of pre-adsorbates on {001} faceted anatase TiO_2 photoanode are obviously greater than those obtained at {101} faceted anatase TiO_2 photoanode, further verifying the higher photocatalytic activity of {001} facets of anatase TiO_2.This work provided a facile photoelectrochemical method to quantitatively determine the photocatalytic oxidation activity of specific exposed crystal facets of a photocatalyst, which would be helpful to uncover and meaningfully compare the intrinsic photocatalytic activities of different exposed crystal facets of a photocatalyst.展开更多
Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, t...Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, the obtained functional magnetic microspheres as heterogeneous catalysts showed superior performance in catalyzing the epoxidation of styrene with extraordinary high conversion （89.5%） and selectivity （90.8%） towards styrene oxide. It is believed that the construction process of these fascinating materials features many implications for creating other functional nanocomposites.展开更多
This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles w...This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles were synthesized in a wide temperature range below 230°C. The composition, morphology, and methylene blue (MB) decoloration characteristics of the obtained products were investigated by X-ray diffraction, Fourier transform infrared spectroscope, X-ray photoelectron spectroscope, and scanning and transmission electron microscope. The dehydrating polycondensation of Ti(IV)-hydrates and the decomposition of (NH4)2Ti3O7 intermediates with the temperature increase lead to the direct formation of anatase TiO2 nanoparticles under the hydrothermal environments. The strong MB decoloration of the hydrothermal products obtained at the low (≤130°C) and high (≥180°C) temperatures are attributed to the adsorption of Ti(IV)-hydrates and the photocatalysis of anatase TiO2 nanoparticles, respectively.展开更多
A vertically aligned anatase TiO2 （A-TiO2） nanotube array has been fabricated by coating a ZnO nanorod （NR） template with a TiO2 precursor solution. After coating, the ZnO NR cores were selectively etched in an ac...A vertically aligned anatase TiO2 （A-TiO2） nanotube array has been fabricated by coating a ZnO nanorod （NR） template with a TiO2 precursor solution. After coating, the ZnO NR cores were selectively etched in an acidic environment to form TiO2 nanotubes （NTs）. More specifically, after growing the ZnO NRs via a hydrothermal method, one drop of the TiO2 precursor solution was cast to coat the ZnO NRs, the tops of which were previously covered with chemical capping materials by electrostatic interaction, and then the sample was sintered. Finally, the sample was immersed in an acidic solution resulting in selective etching of the ZnO NR cores. Thus, only TiO2 NTs remained on the substrate. The capping material is effectively used to create a perfect, hexagonal open-ended TiO2 NT array, which interestingly extends onset absorption towards the visible region.展开更多
基金the Zhejinag Provincial Natural Science Foundation of China(Z4080021 and Y4090067)the Doctoral Fund of the Ministry of Education of China(20100101110039)
文摘In this paper. Glucose, nitrate, and urea were respectively used as C, B, and N sources doped TiO2 at low temperature sol gel method, The obtained nano TiO2 was characterized by DRS, FIRT, TG-DTG. The photocatalytic properties and the optical response range of the natase nanocrystalline were analyzed and studied with the hybrid orbital theory. The results show that the band gap of the doped TiO2 was narrow, and the photocatalytic ability could be excited by the visible lighL and the doping of non metallic elements broadens the application range of TiO2, so that it could be excited under the visible light and obtained better use value.
基金supported by the National Natural Science Foundation of China (51372248, 51432009 and 51272255)the CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences, Chinathe CAS Pioneer Hundred Talents Program
文摘The facet-dependent photocatalytic performance of TiO_2 nanocrystals has been extensively investigated due to their promising applications in renewable energy and environmental fields. However, the intrinsic distinction in the photocatalytic oxidation activities between the {001}and {101} facets of anatase TiO_2 nanocrystals is still unclear and under debate. In this work, a simple photoelectrochemical method was employed to meaningfully quantify the intrinsic photocatalytic activities of {001} and{101} faceted TiO_2 nanocrystal photoanodes. The effective surface areas of photoanodes with different facets were measured based on the monolayer adsorption of phthalic acid on TiO_2 photoanode surface by an ex situ photoelectrochemical method, which were used to normalize the photocurrents obtained from different faceted photoanodes for meaningful comparison of their photocatalytic activities. The results demonstrated that the {001} facets of anatase TiO_2 nanocrystals exhibited much better photocatalytic activity than that of {101} facets of anatase TiO_2 nanocrystals toward photocatalytic oxidation of water and organic compounds with different functional groups(e.g.,–OH, –CHO, –COOH). Furthermore, the instantaneous kinetic constants of photocatalytic oxidation of pre-adsorbates on {001} faceted anatase TiO_2 photoanode are obviously greater than those obtained at {101} faceted anatase TiO_2 photoanode, further verifying the higher photocatalytic activity of {001} facets of anatase TiO_2.This work provided a facile photoelectrochemical method to quantitatively determine the photocatalytic oxidation activity of specific exposed crystal facets of a photocatalyst, which would be helpful to uncover and meaningfully compare the intrinsic photocatalytic activities of different exposed crystal facets of a photocatalyst.
文摘Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, the obtained functional magnetic microspheres as heterogeneous catalysts showed superior performance in catalyzing the epoxidation of styrene with extraordinary high conversion （89.5%） and selectivity （90.8%） towards styrene oxide. It is believed that the construction process of these fascinating materials features many implications for creating other functional nanocomposites.
基金supported by the Ministry of Science and Technology of China (Grant No. 2010CB631004)the Fundamental Research Funds for the Central Universities (Grant Nos. 1112021302, 1106021343, 1116021301)+1 种基金the PAPD and National Natural Science Foundation of China (Grant Nos. 50831004, 11004098, 51171078)the research fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province (Grant No. AE201015)
文摘This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles were synthesized in a wide temperature range below 230°C. The composition, morphology, and methylene blue (MB) decoloration characteristics of the obtained products were investigated by X-ray diffraction, Fourier transform infrared spectroscope, X-ray photoelectron spectroscope, and scanning and transmission electron microscope. The dehydrating polycondensation of Ti(IV)-hydrates and the decomposition of (NH4)2Ti3O7 intermediates with the temperature increase lead to the direct formation of anatase TiO2 nanoparticles under the hydrothermal environments. The strong MB decoloration of the hydrothermal products obtained at the low (≤130°C) and high (≥180°C) temperatures are attributed to the adsorption of Ti(IV)-hydrates and the photocatalysis of anatase TiO2 nanoparticles, respectively.
文摘A vertically aligned anatase TiO2 （A-TiO2） nanotube array has been fabricated by coating a ZnO nanorod （NR） template with a TiO2 precursor solution. After coating, the ZnO NR cores were selectively etched in an acidic environment to form TiO2 nanotubes （NTs）. More specifically, after growing the ZnO NRs via a hydrothermal method, one drop of the TiO2 precursor solution was cast to coat the ZnO NRs, the tops of which were previously covered with chemical capping materials by electrostatic interaction, and then the sample was sintered. Finally, the sample was immersed in an acidic solution resulting in selective etching of the ZnO NR cores. Thus, only TiO2 NTs remained on the substrate. The capping material is effectively used to create a perfect, hexagonal open-ended TiO2 NT array, which interestingly extends onset absorption towards the visible region.
