A cationic block copolymer of poly(1-vinyl-3-ethylimidazolium bromide)and poly(N-isopropylacrylamide),abbreviated as PVEIM-b-PNIPAM,is used as a thermo-switch and a stabilizer to fabricate a novel thermo-sensitive gra...A cationic block copolymer of poly(1-vinyl-3-ethylimidazolium bromide)and poly(N-isopropylacrylamide),abbreviated as PVEIM-b-PNIPAM,is used as a thermo-switch and a stabilizer to fabricate a novel thermo-sensitive graphene–gold nanocomposite via electrostatic interactions,one-pot in situ growth,and chemical reduction.The morphology,chemical structure,and thermosensitivity of the nanocomposite are systematically characterized,which manifests that the PVEIM-b-PNIPAM stabilizer leads to uniformly distributed gold nanoparticles(GNPs)on the surface of reduced graphene oxide(RGO).The new nanocomposite has good dispersibility and high catalytic activity for the reduction of 4-nitrophenol.In addition,the phase transition of this nanocomposite can be reversibly modulated by temperature in water,which results in significantly different catalytic activities depending on the temperature.This thermo-sensitive nanocomposite may be applied as a thermo-switch material for heterogeneous catalysis,sensors,smart material devices etc.展开更多
Graphene quantum dots(GQDs)have attracted great attention because of their possible applications in various fields.Here we report a facile one-step method for the fabrication of a type of white-light-emitting GQD(W-GQ...Graphene quantum dots(GQDs)have attracted great attention because of their possible applications in various fields.Here we report a facile one-step method for the fabrication of a type of white-light-emitting GQD(W-GQD)by NaBH4 reduction.The highly-pure white-light emission of the obtained W-GQDs was confirmed by calculating the Commission International de l’Éclairage(CIE)1931 chromaticity parameters(x=0.30,0.36)from the fluorescence luminescence data.We observed an important increase in the absolute quantum yield from 0.20%to 3.62%before and after the chemical reduction.展开更多
基金supported by the research funds from the National Natural Science Foundation of China(21606081).
文摘A cationic block copolymer of poly(1-vinyl-3-ethylimidazolium bromide)and poly(N-isopropylacrylamide),abbreviated as PVEIM-b-PNIPAM,is used as a thermo-switch and a stabilizer to fabricate a novel thermo-sensitive graphene–gold nanocomposite via electrostatic interactions,one-pot in situ growth,and chemical reduction.The morphology,chemical structure,and thermosensitivity of the nanocomposite are systematically characterized,which manifests that the PVEIM-b-PNIPAM stabilizer leads to uniformly distributed gold nanoparticles(GNPs)on the surface of reduced graphene oxide(RGO).The new nanocomposite has good dispersibility and high catalytic activity for the reduction of 4-nitrophenol.In addition,the phase transition of this nanocomposite can be reversibly modulated by temperature in water,which results in significantly different catalytic activities depending on the temperature.This thermo-sensitive nanocomposite may be applied as a thermo-switch material for heterogeneous catalysis,sensors,smart material devices etc.
基金supported by the Natural Science Foundation of China(21671046,21161003,21364002,21502028 and 51562001)the Guangxi Natural Science Foundation of China(2013GXNSFGA019001,2012GXNSFDA053007 and 2015GX NSFAA139037)+1 种基金the Program for New Century Excellent Talents in University of the Ministry of Education(NCET-13-0743)the Open-End fund of Beijing National Laboratory for Molecular Sciences,the Program for New Century National Hundred,Thousand and Ten Thousand Talent Project of Guangxi,and the State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources(CMEMR2015-A02,CMEMR2013-A08 and CMEMR2013-A013).
文摘Graphene quantum dots(GQDs)have attracted great attention because of their possible applications in various fields.Here we report a facile one-step method for the fabrication of a type of white-light-emitting GQD(W-GQD)by NaBH4 reduction.The highly-pure white-light emission of the obtained W-GQDs was confirmed by calculating the Commission International de l’Éclairage(CIE)1931 chromaticity parameters(x=0.30,0.36)from the fluorescence luminescence data.We observed an important increase in the absolute quantum yield from 0.20%to 3.62%before and after the chemical reduction.
