Monodisperse Mesoporous Carbon Nanoparticles from Polymer/Silica Self-Aggregates and Their Electrocatalytic Activities

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• 作者：Xiaoxi Huang ; Li-Jing Zhou ; Damien Voiry ; Manish Chhowalla ; Xiaoxin Zou ; Tewodros Asefa
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：July 27, 2016
• 年：2016
• 卷：8
• 期：29
• 页码：18891-18903
• 全文大小：885K
• 年卷期：0
• ISSN：1944-8252

文摘

In our quest to make various chemical processes sustainable, the development of facile synthetic routes and inexpensive catalysts can play a central role. Herein we report the synthesis of monodisperse, polyaniline (PANI)-derived mesoporous carbon nanoparticles (PAMCs) that can serve as efficient metal-free electrocatalysts for the hydrogen peroxide reduction reaction (HPRR) as well as the oxygen reduction reaction (ORR) in fuel cells. The materials are synthesized by polymerization of aniline with the aid of (NH₄)₂S₂O₈ as oxidant and colloidal silica nanoparticles as templates, then carbonization of the resulting PANI/silica composite material at different high temperatures, and finally removal of the silica templates from the carbonized products. The PAMC materials that are synthesized under optimized synthetic conditions possess monodisperse mesoporous carbon nanoparticles with an average size of 128 ± 12 nm and an average pore size of ca. 12 nm. Compared with Co₃O₄, a commonly used electrocatalyst for HPRR, these materials show much better catalytic activity for this reaction. In addition, unlike Co₃O₄, the PAMCs remain relatively stable during the reaction, under both basic and acidic conditions. The nanoparticles also show good electrocatalytic activity toward ORR. Based on the experimental results, PAMCs’ excellent electrocatalytic activity is attributed partly to their heteroatom dopants and/or intrinsic defect sites created by vacancies in their structures and partly to their high porosity and surface area. The reported synthetic method is equally applicable to other polymeric precursors (e.g., polypyrrole (PPY)), which also produces monodisperse, mesoporous carbon nanoparticles in the same way. The resulting materials are potentially useful not only for electrocatalysis of HPRR and ORR in fuel cells but also for other applications where high surface area, small sized, nanostructured carbon materials are generally useful for (e.g., adsorption, supercapacitors, etc.).