writer：Wen-Jun Niu, Rong-Hui Zhu, Yan-Hua, Hai-Bo Zeng, Serge Cosnier, Xue-Ji Zhang, Dan Shan*
keywords：N-Cdots; Graphene oxide; N-Cdots/GO hybrid; Electrocatalyst; ORR
source：期刊
specific source：Carbon
Issue time：2016年

In this study, nitrogen-rich carbon dots decorated graphene oxide (N-Cdots/GO) hybrid, as a metal-free electrocatalyst for oxygen reduction reaction (ORR), is synthesized by a facile and low-cost hydrothermal treatment for the first time. Specifically, as a nitrogen-rich bridge-molecule, urea can trap free citric acid on planar planes, edges, and wrinkle sections of GO through amidation reaction in the initial stage. Then, polymer-like intermediates are in situ formed and carbonized to N-Cdots on GO. Owing to the simultaneous N-doping into both Cdots and GO characterized by XPS, as well as the formation of defective graphitic structures analyzed by Raman spectra, the as-prepared hybrid displays a remarkable electrocatalytic performance with more positive onset potential (0.13 V vs. Ag/AgCl) and high kinetic current density (up to 18.4 mA cm?2 at ?0.70 V) comparable to commercial Pt/C catalyst. Furthermore, it demonstrates significantly higher catalytic efficiency (nearly 100% of four-electron ORR pathway) than those of N-Cdots or N-Cdots/GO mixture with an outstanding cyclic stability and superior methanol tolerance capability in alkaline solution.