做氮的 graphene 是为氧减小反应(ORR ) 的高贵基于金属的 electrocatalysts 的代替的一个有希望的候选人。进做氮的 graphene 的毛孔和洞的增加由介绍丰富的暴露的边提高 ORR 活动,加速集体转移,并且阻碍 graphene 表的聚集。此处,我们在场为经由脲和镁醋酸盐 tetrahydrate 的热分解产生多孔的有穴的做氮的 graphene (PHNG ) 的直接却有效的策略。由于联合效果在里面 situ 产生了气体和 MgO nanoparticles,综合 PHNG 在弄皱的 graphene 之中展示了不仅众多的 out-of-plane 毛孔在装配 graphene 的表,而且贯穿的 nanoscale (5-15 nm ) 洞。而且,做 PHNG 的配置的氮被 thermal 以后处理在不同温度优化。pyridinic 和第四级的氮的全面内容断然与 ORR 活动相关,这被发现;特别地, pyridinic 氮为 ORR 产生最理想的特征。这个工作为基于 PHNG 的材料的合成揭示新线路并且阐明到 ORR 的各种各样的氮种类的贡献。
Nitrogen-doped graphene is a promising candidate for the replacement of noble metal-based electrocatalysts for oxygen reduction reactions (ORRs). The addition of pores and holes into nitrogen-doped graphene enhances the ORR activity by introducing abundant exposed edges, accelerating mass transfer, and impeding aggregation of the graphene sheets. Herein, we present a straightforward but effective strategy for generating porous holey nitrogen-doped graphene (PHNG) via the pyrolysis of urea and magnesium acetate tetrahydrate. Due to the combined effects of the in situ generated gases and MgO nanoparticles, the synthesized PHNGs featured not only numerous out-of-plane pores among the crumpled graphene sheets, but also interpenetrated nanoscale (5-15 nm) holes in the assembled graphene. Moreover, the nitrogen doping configurations of PHNG were optimized by post-thermal treatments at different temperatures. It was found that the overall content of pyridinic and quaternary nitrogen positively correlates with the ORR activity; in particular, pyridinic nitrogen generates the most desirable characteristics for the ORR. This work reveals new routes for the synthesis of PHNG-based materials and elucidates the contributions of various nitrogen species to ORRs.