Controllable synthesis of mesoporous carbon nanospheres and Fe-N/carbon nanospheres as efficient oxygen reduction electrocatalysts
MetadataShow full item record
The synthesis of mesoporous carbon nanospheres (MCNs), especially with diameters below 200 nm remains a great challenge due to weak interactions between the carbon precursors and soft templates, as well as the uncontrollable cross-linking rate of carbon precursors. Herein, we demonstrate a simple acid-assisted, hydrothermal synthesis approach to synthesizing such uniform MCNs with well controlled diameters ranging from 20 to 150 nm under highly acidic conditions (2 M HCl). Both the carbon precursor and the template are partly protonated under such conditions and show additional Coulombic interactions with chloride ions (acts as mediators). This kind of enhanced interaction is similar to that of the “I+X−S+” mechanism in the synthesis of mesoporous metal oxide, which can effectively retard the cross-linking rate of resol molecules and avoid macroscopic phase separation during the hydrothermal synthesis. Due to their uniform spherical morphology, small diameter, and high surface areas, MCNs can be modified with Fe and N species via impregnation of cheap precursors (ferric nitrate and dicyandiamide), which are further converted into nonprecious electrocatalysts for oxygen reduction reactions. The resulting Fe–N/MCNs exhibit high catalytic activities, long-term stability and improved methanol tolerance under alkaline conditions, which can be potentially used in direct methanol fuel cells and metal-air batteries.
Showing items related by title, author, creator and subject.
Revisiting the Stöber method: Design of nitrogen-doped porous carbon spheres from molecular precursors of different chemical structuresTian, H.; Liu, Juan; O'Donnell, K.; Liu, T.; Liu, X.; Yan, Z.; Liu, Shaomin; Jaroniec, M. (2016)© 2016 Elsevier Inc. Porous polymer resins and carbon spheres have been successfully prepared by an extended Stöber method using phenol derivatives of different functionality. Herein, the Stöber method is revised and used ...
Liu, Jian; Yang, T.; Wang, D.; Lu, G.; Zhao, D.; Qiao, S. (2013)Owing to the weak self-assembly ability of precursor components and the serious crosslinking of neighbouring nanospheres during a hydrothermal process, the synthesis of monodisperse mesoporous polymer nanospheres with ...
Ballmilling-assisted synthesis and electrochemical performance of LiFePO<inf>4</inf>/C for lithium-ion battery adopting citric acid as carbon precursorZhang, D.; Yu, X.; Wang, Y.; Cai, R.; Shao, Zongping; Liao, X.; Ma, Z. (2009)LiFePO4/C composite cathode for secondary lithium-ion battery was synthesized via a mechanochemical activation/sintering process adopting citric acid (CA) as carbon source. The carbon formation process, optimal carbon ...