摘要
Heteroatom-doped nanocarbons have excellent potential for use in the oxygen reduction reaction （ORR）. However, construction of three-dimensional （3D） N-doped carbon materials with good electrocatalytic performance remains a challenge. Herein, a poly（p-phenylenevinylene） （PPV）-precursor adhesion route was developed for construction of 3D N-doped reduced graphene oxide-PPV calcined-carbon nanotubes （N-RGO-PPV（c）-CNTs）. In the synthesis, the PPV- precursor plays the role of a ＂glue＂ for strong adhesion of the RGO and CNTs. At high temperature, PPV can undergo transformation from the glassy state to a viscous state. Thus, the N-RGO-PPV（c）-CNT composite with multi-porous structure and ridge-like folded graphene flakes could be formed during nitridation at high temperature, which was favorable for production of more active sites for the ORR. As an ORR catalyst, the N-RGO-PPV（c）-CNT composites exhibited superior catalytic activity in alkaline electrolyte. The obtained onset potential （Eonset） of 0.92 V and catalytic current density of 5.7 mA·cm^-2 at 0.6 V （vs. RHE） are comparable to those of the 20% Pt/C composite （0.98 V and 5.2 mA·cm^-2）. The electron transfer number for the N-RGO-PPV（c）-CNT catalyst was about 3.99, which is close to that of the 20% Pt/C （4.01） catalyst. Notably, the optimal N-RGO-PPV（c）-CNT catalyst shows better durability and methanol tolerance than commercial 20% Pt/C. The good performance of the N-RGO-PPV（c）-CNT catalyst for the ORR may be attributed to the synergistic effects of the unique 3D structure for effective mass-transfer, the effective N-doping for production of more active sites, and the good contact between the RGO and CNTs for easy charge-transfer.
Heteroatom-doped nanocarbons have excellent potential for use in the oxygen reduction reaction （ORR）. However, construction of three-dimensional （3D） N-doped carbon materials with good electrocatalytic performance remains a challenge. Herein, a poly（p-phenylenevinylene） （PPV）-precursor adhesion route was developed for construction of 3D N-doped reduced graphene oxide-PPV calcined-carbon nanotubes （N-RGO-PPV（c）-CNTs）. In the synthesis, the PPV- precursor plays the role of a ＂glue＂ for strong adhesion of the RGO and CNTs. At high temperature, PPV can undergo transformation from the glassy state to a viscous state. Thus, the N-RGO-PPV（c）-CNT composite with multi-porous structure and ridge-like folded graphene flakes could be formed during nitridation at high temperature, which was favorable for production of more active sites for the ORR. As an ORR catalyst, the N-RGO-PPV（c）-CNT composites exhibited superior catalytic activity in alkaline electrolyte. The obtained onset potential （Eonset） of 0.92 V and catalytic current density of 5.7 mA·cm^-2 at 0.6 V （vs. RHE） are comparable to those of the 20% Pt/C composite （0.98 V and 5.2 mA·cm^-2）. The electron transfer number for the N-RGO-PPV（c）-CNT catalyst was about 3.99, which is close to that of the 20% Pt/C （4.01） catalyst. Notably, the optimal N-RGO-PPV（c）-CNT catalyst shows better durability and methanol tolerance than commercial 20% Pt/C. The good performance of the N-RGO-PPV（c）-CNT catalyst for the ORR may be attributed to the synergistic effects of the unique 3D structure for effective mass-transfer, the effective N-doping for production of more active sites, and the good contact between the RGO and CNTs for easy charge-transfer.
基金
This work was financially supported by the National Natural Science Foundation of China （Nos. 51433003, 21401048 and 21571054）.
