Chen Tongzhou, Chi Yongbo, Liu Xingyao, Xia Xiwen, Chen Yousi, Xu Jian, Song Yujie
State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials Oriented Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Materials (Basel). 2022 Aug 29;15(17):5955. doi: 10.3390/ma15175955.
Heteroatom-doped conductive carbon nanomaterials are promising for energy and catalysis applications, but there are few reports on increasing their heteroatom doping content and conductivity simultaneously. In this manuscript, we use 2-(4-aminophenyl)-5-aminobenzimidazole as the diamine monomer to prepare polyamic acid with asymmetric structural units doped with phosphoric acid (PA) and polyacrylonitrile (PAN) as innovative composite precursors, which are then electrospun into nanofiber films. After stabilization and carbonization, the electrospun fibers are converted into N/P co-doped electrospun carbon nanofiber films (ECNFs) with high heteroatom content, including 4.33% N and 0.98% P. The morphology, structure, and conductivity of ECNFs were systematically characterized. The ECNFs doped with 15 wt.% PA exhibited conductivity that was 47.3% higher than that of the ECNFs undoped with PA, but the BET surface area decreased by 23%. The doped PA in the precursor nanofibers participated in the cyclization of PAN during thermal stabilization, as indicated by infrared spectroscopy and thermogravimetric analysis results. X-ray diffraction and Raman results indicate that a moderate amount of PA doping facilitated the formation of ordered graphitic crystallite structures during carbonization and improved the conductivity of ECNFs.
杂原子掺杂的导电碳纳米材料在能源和催化应用方面具有广阔前景，但关于同时提高其杂原子掺杂含量和电导率的报道却很少。在本论文中，我们使用2-(4-氨基苯基)-5-氨基苯并咪唑作为二胺单体，制备了具有不对称结构单元且掺杂有磷酸（PA）的聚酰胺酸以及聚丙烯腈（PAN）作为创新型复合前驱体，随后将它们静电纺丝成纳米纤维膜。经过稳定化处理和碳化后，静电纺丝纤维转变为具有高杂原子含量的N/P共掺杂静电纺丝碳纳米纤维膜（ECNFs），其中氮含量为4.33%，磷含量为0.98%。我们系统地表征了ECNFs的形貌、结构和电导率。掺杂15 wt.% PA的ECNFs的电导率比未掺杂PA的ECNFs高47.3%，但其比表面积下降了23%。红外光谱和热重分析结果表明，前驱体纳米纤维中掺杂的PA在热稳定化过程中参与了PAN的环化反应。X射线衍射和拉曼光谱结果表明，适量的PA掺杂有助于在碳化过程中形成有序的石墨微晶结构，并提高了ECNFs的电导率。
