Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermal...Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers （HP-NCNFs） through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m2-g 1, which is 2.6 times higher than that （323.2 m2.g 1） of conventional N-doped carbon nanofibers （NCNFs）. Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction （ORR） in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commerdal Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional （3D） cross-linked structures, graphene-like structure on the edge of the HP- NCNFs, high specific surface area, and a hierarchically porous structure.展开更多
基金This work was financially supported by the National Natural Science Foundation of China （Nos. 21471016 and 21271023） and the 111 Project （No. B07012）.
文摘Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers （HP-NCNFs） through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m2-g 1, which is 2.6 times higher than that （323.2 m2.g 1） of conventional N-doped carbon nanofibers （NCNFs）. Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction （ORR） in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commerdal Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional （3D） cross-linked structures, graphene-like structure on the edge of the HP- NCNFs, high specific surface area, and a hierarchically porous structure.
