TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrys...TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrystal films by a direct annealing method.The morphology and crystal phase of the film were controlled by adjusting the ratio of NH4F and the calcination temperature.Moreover,we found that Au nanoparticles loaded on a TiO2 mesocrystal film enabled highly efficient visible light photocatalytic properties.The photocatalytic activities were studied by hydrogen generation and photoreduction of Cr(VI).This work represents a considerable advance in the development and application of the TiO2 mesocrystals.展开更多
Ordered mesoporous Fe/TiO2 was prepared by an evaporation-induced self-assembly method. The iron ions were in situ embedded in the pore wall of the TiO2 framework. The catalyst has excellent light-assisted Fenton cata...Ordered mesoporous Fe/TiO2 was prepared by an evaporation-induced self-assembly method. The iron ions were in situ embedded in the pore wall of the TiO2 framework. The catalyst has excellent light-assisted Fenton catalytic performance under UV and visible light irradiation. X-ray diffraction and transmission electron microscopy results showed that the TiO2 samples have an ordered two-dimensional hexagonal pore structure and an anatase phase structure with high crystallinity. The ordered pore structure of the TiO2 photocatalyst with a large specific surface area is beneficial to mass transfer and light harvesting. Furthermore, iron ions can be controlled by embedding them into the TiO2 framework to prevent iron ion loss and inactivation. After five cycles, the reaction rate of the ordered mesoporous Fe/TiO2 remained unchanged, indicating that the material has stable performance and broad application prospects for the purification of environmental pollutants.展开更多
以ω-溴-α-酮酸为原料,发展了一种合成手性α,ω-二氨基酸的高效方法,通过手性吡哆胺催化ω-溴-α-酮酸的不对称转氨化和NH 3 对ω-溴的取代反应,在温和条件下一锅法合成了6个带有不同长度直链手性α,ω-二氨基酸,收率49~93%, ee 值最...以ω-溴-α-酮酸为原料,发展了一种合成手性α,ω-二氨基酸的高效方法,通过手性吡哆胺催化ω-溴-α-酮酸的不对称转氨化和NH 3 对ω-溴的取代反应,在温和条件下一锅法合成了6个带有不同长度直链手性α,ω-二氨基酸,收率49~93%, ee 值最高可以达91%,其结构经 1 H NMR和 13 C NMR表征。展开更多
Combining microwave radiation with photocatalytic systems is a promising method to inhibit photogenerated electron-hole recombination and enhance the photocatalytic reaction performance. In this study, we have designe...Combining microwave radiation with photocatalytic systems is a promising method to inhibit photogenerated electron-hole recombination and enhance the photocatalytic reaction performance. In this study, we have designed Pd/Pb TiO3 catalysts that can use both microwave fields and photocatalysis. Benefiting from the synergistic effect of microwave field and UV light, the Pb TiO3 crystals convert thermal energy into electrical energy via the pyroelectricity effect, generating positive and negative charges(q+ and q-), while Pd nanoparticles significantly improve the quantum efficiency of the photocatalytic process. The composite catalyst significantly enhances the reaction rate and selectivity of the model Suzuki coupling reaction performed with bromobenzene. Microwave fields can directly act on chemical systems, promoting or changing various chemical reactions in unique ways.展开更多
Heterostructure photocatalysts with a built-in electric field have become one of the most promising strategies to enhance photogenerated electron-hole pair separation. However, close contact between the two active com...Heterostructure photocatalysts with a built-in electric field have become one of the most promising strategies to enhance photogenerated electron-hole pair separation. However, close contact between the two active components of heterogeneous photocatalysts remains a problem. Herein, the in-situ fabrication of an SnO2/SnS2 heterostructure photocatalyst was performed;the structure showed enhanced photocatalytic performance resulting from the tight-contact heterostructures. The results of photoelectrochemical measurements further verified that a tight-contact heterostructure improved the separation of photogenerated electron-hole pairs. The results of EIS Bode plots also demonstrated that such in-situ fabricated SnO2/SnS2 samples exhibited the longest carrier lifetime(41.6 μs) owing to the intimate interface of SnO2/SnS2 heterostructures.展开更多
文摘TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrystal films by a direct annealing method.The morphology and crystal phase of the film were controlled by adjusting the ratio of NH4F and the calcination temperature.Moreover,we found that Au nanoparticles loaded on a TiO2 mesocrystal film enabled highly efficient visible light photocatalytic properties.The photocatalytic activities were studied by hydrogen generation and photoreduction of Cr(VI).This work represents a considerable advance in the development and application of the TiO2 mesocrystals.
基金supported by the National Natural Science Foundation of China(21273149)the Program for New Century Excellent Talents in University(NCET-11-1052)the Shanghai Science & Technology and Education Committee(11JC1408900,12490502800,10SG41,12YZ084)~~
基金supported by the National Natural Science Foundation of China(21876114,21761142011,51572174)Shanghai Government(17SG44)+2 种基金International Joint Laboratory on Resource Chemistry(IJLRC)Ministry of Education of China(PCSIRT_IRT_16R49)supported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning and Shuguang Research Program of Shanghai Education Committee~~
文摘Ordered mesoporous Fe/TiO2 was prepared by an evaporation-induced self-assembly method. The iron ions were in situ embedded in the pore wall of the TiO2 framework. The catalyst has excellent light-assisted Fenton catalytic performance under UV and visible light irradiation. X-ray diffraction and transmission electron microscopy results showed that the TiO2 samples have an ordered two-dimensional hexagonal pore structure and an anatase phase structure with high crystallinity. The ordered pore structure of the TiO2 photocatalyst with a large specific surface area is beneficial to mass transfer and light harvesting. Furthermore, iron ions can be controlled by embedding them into the TiO2 framework to prevent iron ion loss and inactivation. After five cycles, the reaction rate of the ordered mesoporous Fe/TiO2 remained unchanged, indicating that the material has stable performance and broad application prospects for the purification of environmental pollutants.
文摘以ω-溴-α-酮酸为原料,发展了一种合成手性α,ω-二氨基酸的高效方法,通过手性吡哆胺催化ω-溴-α-酮酸的不对称转氨化和NH 3 对ω-溴的取代反应,在温和条件下一锅法合成了6个带有不同长度直链手性α,ω-二氨基酸,收率49~93%, ee 值最高可以达91%,其结构经 1 H NMR和 13 C NMR表征。
文摘Combining microwave radiation with photocatalytic systems is a promising method to inhibit photogenerated electron-hole recombination and enhance the photocatalytic reaction performance. In this study, we have designed Pd/Pb TiO3 catalysts that can use both microwave fields and photocatalysis. Benefiting from the synergistic effect of microwave field and UV light, the Pb TiO3 crystals convert thermal energy into electrical energy via the pyroelectricity effect, generating positive and negative charges(q+ and q-), while Pd nanoparticles significantly improve the quantum efficiency of the photocatalytic process. The composite catalyst significantly enhances the reaction rate and selectivity of the model Suzuki coupling reaction performed with bromobenzene. Microwave fields can directly act on chemical systems, promoting or changing various chemical reactions in unique ways.
文摘Heterostructure photocatalysts with a built-in electric field have become one of the most promising strategies to enhance photogenerated electron-hole pair separation. However, close contact between the two active components of heterogeneous photocatalysts remains a problem. Herein, the in-situ fabrication of an SnO2/SnS2 heterostructure photocatalyst was performed;the structure showed enhanced photocatalytic performance resulting from the tight-contact heterostructures. The results of photoelectrochemical measurements further verified that a tight-contact heterostructure improved the separation of photogenerated electron-hole pairs. The results of EIS Bode plots also demonstrated that such in-situ fabricated SnO2/SnS2 samples exhibited the longest carrier lifetime(41.6 μs) owing to the intimate interface of SnO2/SnS2 heterostructures.
