Carbon-based metal-free catalysts are a promising substitute for the rare and expensive platinum （Pt） used in the oxygen reduction reaction. We herein report N-doped graphene （NG） that is exquisitely integrated in...Carbon-based metal-free catalysts are a promising substitute for the rare and expensive platinum （Pt） used in the oxygen reduction reaction. We herein report N-doped graphene （NG） that is exquisitely integrated into highly conductive frameworks, simultaneously providing more active sites and higher conductivity. The NG was in situ grown on carbon fibers derived from silk cocoon （SCCf） using a simple one-step thermal treatment. The resulting product （NG-SCCf）, possessing a meso-/macroporous structure with three-dimensional （3D） interconnected networks, exhibits an onset potential that is only 0.1 V less negative than that of Pt/C and shows stability and methanol tolerance superior to those of Pt/C in alkaline media. Moreover, in the absence of Pt as co-catalyst, NG-SCCf shows a photocatalytic H2 production rate of 66.0 ~tmol-h l.g 1, 4.4-fold higher than that of SCCf. This outstanding activity is intimately related to the in situ grown NG, hierarchically porous structure, and 3D interconnected networks, which not only introduce more active sites but also enable smooth electron transfer, mass transport, and effective separation of electron-hole pairs. Considering the abundance of the green raw material in combination with easy and low-cost preparation, this work contributes to the development of advanced sustainable catalysts in energy storage/conversion fields, such as electro- and photocatalysis.展开更多
基金The work was financially supported by National Natural Science Foundation of China （Nos. 51203182 and 51173202）, Foundation for the Author of Excellent Doctoral Dissertation of Hunan Province （No. YB2014B004）, Aeronautical Science Foundation of China （No. 20143188004）, Key Laboratory of Advanced Textile Materials and Manufacturing Technology （Zhejiang Sci-Tech University）, Ministry of Education （No. 2015001）, Key Laboratory of Lightweight and Reliability Technology for Engineering Vehicle, College of Hunan Province （No. 2016kfjj01）, Research Project of NUDT. We thank Tengyuan Wang for help in ORR experiment and helpful discussions.
文摘Carbon-based metal-free catalysts are a promising substitute for the rare and expensive platinum （Pt） used in the oxygen reduction reaction. We herein report N-doped graphene （NG） that is exquisitely integrated into highly conductive frameworks, simultaneously providing more active sites and higher conductivity. The NG was in situ grown on carbon fibers derived from silk cocoon （SCCf） using a simple one-step thermal treatment. The resulting product （NG-SCCf）, possessing a meso-/macroporous structure with three-dimensional （3D） interconnected networks, exhibits an onset potential that is only 0.1 V less negative than that of Pt/C and shows stability and methanol tolerance superior to those of Pt/C in alkaline media. Moreover, in the absence of Pt as co-catalyst, NG-SCCf shows a photocatalytic H2 production rate of 66.0 ~tmol-h l.g 1, 4.4-fold higher than that of SCCf. This outstanding activity is intimately related to the in situ grown NG, hierarchically porous structure, and 3D interconnected networks, which not only introduce more active sites but also enable smooth electron transfer, mass transport, and effective separation of electron-hole pairs. Considering the abundance of the green raw material in combination with easy and low-cost preparation, this work contributes to the development of advanced sustainable catalysts in energy storage/conversion fields, such as electro- and photocatalysis.
