Photocatalytic H2 evolution reactions on pristine graphitic carbon nitrides(g-C3N4),as a promising approach for converting solar energy to fuel,are attractive for tackling global energy concerns but still suffer from ...Photocatalytic H2 evolution reactions on pristine graphitic carbon nitrides(g-C3N4),as a promising approach for converting solar energy to fuel,are attractive for tackling global energy concerns but still suffer from low efficiencies.In this article,we report a tractable approach to modifying g-C3N4 with vanadyl phthalocyanine(VOPc/CN)for efficient visible-light-driven hydrogen production.A non-covalent VOPc/CN hybrid photocatalyst formed viaπ-πstacking interactions between the two components,as confirmed by analysis of UV-vis absorption spectra.The VOPc/CN hybrid photocatalyst shows excellent visible-light-driven photocatalytic performance and good stability.Under optimal conditions,the corresponding H2 evolution rate is nearly 6 times higher than that of pure g-C3N4.The role of VOPc in promoting hydrogen evolution activity was to extend the visible light absorption range and prevent the recombination of photoexcited electron-hole pairs effectively.It is expected that this facile modification method could be a new inspiration for the rational design and exploration of g-C3N4-based hybrid systems with strong light absorption and high-efficiency carrier separation.展开更多
The thin film properties of organic semiconductors are very important to the device performance.Herein,non-planar vanadyl phthalocyanine(VOPc)thin films grown on rigid substrates of indium tin oxide,silicon dioxide,an...The thin film properties of organic semiconductors are very important to the device performance.Herein,non-planar vanadyl phthalocyanine(VOPc)thin films grown on rigid substrates of indium tin oxide,silicon dioxide,and flexible substrate of kapton by organic molecular beam deposition under vacuum conditions are systematically studied via atomic force microscopy and x-ray diffraction.The results clearly reveal that the morphology and grain size are strongly dependent on the substrate temperature during the process of film deposition.Meanwhile,the VOPc films with the structure of phase I or phase II can be modulated via in situ annealing and post-annealing temperature.Furthermore,the crystalline structure and molecular orientation of vapor-deposited VOPc can be controlled using molecular template layer 3,4,9,10-perylenetetracarboxylic dianhydride(PTCDA),the VOPc film of which exhibits the phase I structure.The deep understanding of growth mechanism of non-planar VOPc film provides valuable information for controlling structure-property relationship and accelerates the application in electronic and optoelectronic devices.展开更多
基金supported by the National Natural Science Foundation of China(20773001,20973004,20973003,50821061)National Key Basic Research Program of China(973)(2006CB806102,2009CB929403)~~
基金supported by the National Natural Science Foundation of China(51572253,21771171)Scientific Research Grant of Hefei National Synchrotron Radiation Laboratory(UN2017LHJJ)+1 种基金the Fundamental Research Funds for the Central Universitiescooperation between NSFC and Netherlands Organization for Scientific Research(51561135011)~~
文摘Photocatalytic H2 evolution reactions on pristine graphitic carbon nitrides(g-C3N4),as a promising approach for converting solar energy to fuel,are attractive for tackling global energy concerns but still suffer from low efficiencies.In this article,we report a tractable approach to modifying g-C3N4 with vanadyl phthalocyanine(VOPc/CN)for efficient visible-light-driven hydrogen production.A non-covalent VOPc/CN hybrid photocatalyst formed viaπ-πstacking interactions between the two components,as confirmed by analysis of UV-vis absorption spectra.The VOPc/CN hybrid photocatalyst shows excellent visible-light-driven photocatalytic performance and good stability.Under optimal conditions,the corresponding H2 evolution rate is nearly 6 times higher than that of pure g-C3N4.The role of VOPc in promoting hydrogen evolution activity was to extend the visible light absorption range and prevent the recombination of photoexcited electron-hole pairs effectively.It is expected that this facile modification method could be a new inspiration for the rational design and exploration of g-C3N4-based hybrid systems with strong light absorption and high-efficiency carrier separation.
基金Project supported by the National Natural Science Foundation of China(Grant No.51673214)the National Key Research and Development Program of China(Grant No.2017YFA0206600)
文摘The thin film properties of organic semiconductors are very important to the device performance.Herein,non-planar vanadyl phthalocyanine(VOPc)thin films grown on rigid substrates of indium tin oxide,silicon dioxide,and flexible substrate of kapton by organic molecular beam deposition under vacuum conditions are systematically studied via atomic force microscopy and x-ray diffraction.The results clearly reveal that the morphology and grain size are strongly dependent on the substrate temperature during the process of film deposition.Meanwhile,the VOPc films with the structure of phase I or phase II can be modulated via in situ annealing and post-annealing temperature.Furthermore,the crystalline structure and molecular orientation of vapor-deposited VOPc can be controlled using molecular template layer 3,4,9,10-perylenetetracarboxylic dianhydride(PTCDA),the VOPc film of which exhibits the phase I structure.The deep understanding of growth mechanism of non-planar VOPc film provides valuable information for controlling structure-property relationship and accelerates the application in electronic and optoelectronic devices.