Abstract Inspired by the truth that the hierarchy structure nanocomposites can exhibit superior electrochemical performance because such structure can provide more electron transfer routes, here we reported the preparation of Fe3O4@N-rGO nanocomposites which can match this point. The power conversion efficiency (PCE) of the cell with Fe3O4 nanoparticle as counter electrode is 6.85% while PCE for the cell with Fe3O4@N-rGO nanocomposites as counter electrode shows great enhancement, and the highest value is up to 8.18%, even higher than Pt's efficiency (7.17%) in the same environment. The great performance can be ascribed to the hierarchy structure of N-rGO and the excellent conductivity of Fe3O4 to achieve dual-functional structure optimization. The 2D hierarchy structure N-rGO film in the hybrids plays two important roles: the more active sites for dispersed Fe3O4 nanoparticles promoting catalytic efficiency and the higher electrical conducting structure for quickly charge transfer. The 2D hierarchy structure N-rGO film will be a great help for Fe3O4 particles as CE application in DSSCs.

中文翻译：

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双功能 Fe 3 O 4 @N-rGO 催化剂作为对电极在染料敏化太阳能电池中具有高性能

摘要 受层次结构纳米复合材料可以提供更多电子传递途径而表现出优异电化学性能这一事实的启发，我们在此报道了符合这一点的Fe3O4@N-rGO纳米复合材料的制备。以Fe3O4纳米颗粒为对电极的电池的功率转换效率（PCE）为6.85%，而以Fe3O4@N-rGO纳米复合材料为对电极的电池的功率转换效率（PCE）有很大的提高，最高值高达8.18%，甚至更高比 Pt 在相同环境下的效率（7.17%）。出色的性能可归因于 N-rGO 的层次结构和 Fe3O4 的优异导电性，实现了双功能结构优化。混合体中的二维层次结构 N-rGO 薄膜起着两个重要的作用：分散的 Fe3O4 纳米颗粒的活性位点越多，催化效率越高，导电结构越高，电荷转移越快。二维层级结构 N-rGO 薄膜将对 Fe3O4 颗粒作为 DSSC 中的 CE 应用有很大帮助。