Enhanced oxygen reduction of multi-Fe3O4@carbon core-shell electrocatalysts through a nanoparticle/polymer co-assembly strategy
Enhanced oxygen reduction of multi-Fe3O4@carbon core-shell electrocatalysts through a nanoparticle/polymer co-assembly strategy
复制标题
通过纳米粒子/聚合物共组装策略增强多Fe3O4@碳核壳电催化剂的氧还原
作者：
Zhao Jing;Li Congling;Liu Rui
本文报道了以Fe3O4纳米粒子与聚苯乙烯-b-聚环氧乙烷（PS-b-PEO）共组装为模板，快速合成multi-Fe3O4@carbon （mFe3O4@C）核壳纳米粒子（NPs）。缓慢的溶剂交换导致多个微小的疏水性Fe3O4 NPs被困在PS-b-PEO胶束中。经聚多巴胺包覆和炭化后，得到包覆多个Fe3O4芯的碳壳。mFe3O4@C的显著特点在于更活跃的Fe3O4位点和碳壳内可用的自由空间。结果表明，合成的mFe3O4@C的氧还原性能比单一的Fe3O4@C表现出更高的起搏电位。同时，mFe3O4@C与商业Pt/C相比，具有更大的极限电流密度（1.0 V时为5.2 mA cm - 2），长时间稳定性和甲醇耐受性。胶束固定化NPs作为模板的通用性有望促进各种核壳NPs的实际应用。
This paper reports a facile synthesis of multi-Fe3O4@carbon (mFe3O4@C) core–shell nanoparticles (NPs) using co-assembly of Fe3O4 NPs and polystyrene-b-poly(ethylene oxide) (PS-b-PEO) as a template. Slow solvent exchange leads to multiple tiny hydrophobic Fe3O4 NPs entrapped within PS-b-PEO micelles. After polydopamine coating and subsequent carbonization, a carbon shell encapsulating multiple Fe3O4 cores is obtained. The significant features of mFe3O4@C lie in the more active Fe3O4 sites and available free space within the carbon shell. As a result, the oxygen reduction performance of the resultant mFe3O4@C shows a higher onset potential than that of single Fe3O4@C. Meanwhile, mFe3O4@C exhibits a larger limiting current density (5.2 mA cm−2 at 1.0 V), long-time stability, and methanol tolerance compared to commercial Pt/C. The generality of the micellar immobilized NPs as a template is expected to boost the fabrication of various core–shell NPs for practical applications.