Nitrogen-doped carbon quantum dot/graphene hybrid nanocomposite as an efficient catalyst support for the oxygen reduction reaction

• Published in: International journal of hydrogen energy 2017-02, Vol.42 (5), p.2931-2942
• Main Authors: Cao, Jianyu, Hu, Yue, Chen, Lijuan, Xu, Juan, Chen, Zhidong
• Format: Article
• Language: English
• Subjects: Carbon quantum dot; Electrocatalyst; Nitrogen doping; Oxygen reduction reaction; Sacrificial template
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2017.01.029

A nitrogen-doped carbon quantum dot/graphene (N-CQD/G) hybrid nanocomposite was synthesized in-situ using a sacrificial template-assisted pyrolysis method with an oligomeric phenolic resin as the carbon source and dicyandiamide as the sacrificial template precursor/nitrogen source. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, atomic force microscopy, nitrogen adsorption–desorption, Raman and X-ray photoelectron spectroscopy were employed to characterize N-CQD/G samples. The Pt nanoparticles were then deposited onto N-CQD/G hybrids (Pt/N-CQD/G) using a polyol reduction method. Structural and morphological investigations for the Pt/N-GQD/G revealed that ultrafine Pt particles with an average size of 2.1 nm, together with CQDs, are uniformly dispersed on the surfaces of graphene nanosheets. Compared with commercial Pt/C catalysts, Pt/N-CQD/G with highly electrochemical active surface area (ca. 123.4 m2 g−1Pt) show remarkably enhanced electrocatalytic activity and durability toward oxygen reduction reaction (ORR). The superior ORR catalytic performance of Pt/N-CQD/G can be attributed to highly distributed Pt nanoparticles with small size, nitrogen-doping, and strong interaction between metal and support, as well as the unique structure of N-CQD/G hybrids which combines the advantages of both carbon quantum dot and graphene, such as abundant edges and doping sites, high surface area, large pore size and high electrical conductivity. [Display omitted] •Nitrogen-doped carbon quantum dot/graphene (N-CQD/G) was synthesized in-situ.•A sacrificial template-assisted pyrolysis method was used to achieve the N-CQD/G.•As the support, the N-CQD/G combines the advantages of both CQD and graphene.•Ultrafine Pt particles, together with CQDs, are uniformly dispersed on graphene.•The Pt/N-CQD/G catalyst shows a superior ORR activity and durability.