Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc w...Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc was characterized using Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible(UV-Vis)spectroscopy.Photoinduced cascading electron/charge transfer from Por to RGO and from RGO to Pc was established from fluorescence,electrochemical,and femtosecond transient absorption(fs-TA)spectroscopy studies.The increased distance between the electron donors and acceptors of the Por-RGO-Pc nanoconjugate compared to the parent materials and the intermediate RGO-Pc results in longlived charge separation,and an enhancement in nonlinear optical(NLO)absorption(a large NLO coefficient of about 827.44 cm/GW)towards nanosecond laser irradiation at 532 nm.展开更多
Edge-functionalization of graphene is emerging as a powerful chemical method for the construction ofπ-delocalized highlyplanar graphene nanoconjugates that are not accessible through surface-supported syntheses.Herei...Edge-functionalization of graphene is emerging as a powerful chemical method for the construction ofπ-delocalized highlyplanar graphene nanoconjugates that are not accessible through surface-supported syntheses.Herein,a graphene-porphyrin nanoconjugate via a robust pyrazine(pz)linkage has been obtained by condensing 2,3-diamino-5,10,15,20-tetraphenylporphyrin(DA-TPP)with ortho-quinone(o-quinone)moieties at edge sites of graphene oxide(GO).The as-prepared GO-pz-TPP exhibits an intense absorption extending from 375 to 900 nm and a high quenching yield(98%)of fluorescence,indicating a strong electronic coupling effect between GO and TPP units.GO-pz-TPP displays strong nonlinear optical(NLO)absorption and giant NLO coefficients with 800 and 1,030 nm fs laser,in sharp contrast to traditional graphene-porphyrin nanohybrids only NLO-active towards ns laser.Such a dramatic NLO performance towards femtosecond pulsed laser has not been achieved in any carbonchromophores nanohybridized materials to date.This work validates theπ-extended edge-functionalization strategy as a means to tune the NLO properties of graphene,thereby providing a new paradigm for the assembly of versatile optoelectronic materials.展开更多
基金Financial support from the National Natural Science Foundation of China(No.51432006)the Ministry of Science and Technology of China for the International Science Linkages Program(No.2011DFG52970)+2 种基金the Ministry of Education of China for the Changjiang Innovation Research Team(No.IRT14R23)the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project(No.B13025)the Innovation Program of Shanghai Municipal Education Commission are gratefully acknowledged.M.G.H thanks the Australian Research Council(No.DP170100411)for support.
文摘Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc was characterized using Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible(UV-Vis)spectroscopy.Photoinduced cascading electron/charge transfer from Por to RGO and from RGO to Pc was established from fluorescence,electrochemical,and femtosecond transient absorption(fs-TA)spectroscopy studies.The increased distance between the electron donors and acceptors of the Por-RGO-Pc nanoconjugate compared to the parent materials and the intermediate RGO-Pc results in longlived charge separation,and an enhancement in nonlinear optical(NLO)absorption(a large NLO coefficient of about 827.44 cm/GW)towards nanosecond laser irradiation at 532 nm.
基金the National Natural Science Foundation of China(No.51432006)the Ministry of Science and Technology of China for the International Science Linkages Program(No.2011DFG52970)+2 种基金the Ministry of Education of China for the Changjiang Innovation Research Team(No.IRT14R23)the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project(No.B13025)the Innovation Program of Shanghai Municipal Education Commission are gratefully acknowledged.M.G.H thanks the Australian Research Council(No.DP170100411)for support.
文摘Edge-functionalization of graphene is emerging as a powerful chemical method for the construction ofπ-delocalized highlyplanar graphene nanoconjugates that are not accessible through surface-supported syntheses.Herein,a graphene-porphyrin nanoconjugate via a robust pyrazine(pz)linkage has been obtained by condensing 2,3-diamino-5,10,15,20-tetraphenylporphyrin(DA-TPP)with ortho-quinone(o-quinone)moieties at edge sites of graphene oxide(GO).The as-prepared GO-pz-TPP exhibits an intense absorption extending from 375 to 900 nm and a high quenching yield(98%)of fluorescence,indicating a strong electronic coupling effect between GO and TPP units.GO-pz-TPP displays strong nonlinear optical(NLO)absorption and giant NLO coefficients with 800 and 1,030 nm fs laser,in sharp contrast to traditional graphene-porphyrin nanohybrids only NLO-active towards ns laser.Such a dramatic NLO performance towards femtosecond pulsed laser has not been achieved in any carbonchromophores nanohybridized materials to date.This work validates theπ-extended edge-functionalization strategy as a means to tune the NLO properties of graphene,thereby providing a new paradigm for the assembly of versatile optoelectronic materials.
