摘要
The design of catalysts that are both highly active and stable is always challenging. Herein, we report that the incorporation of single metal active sites attached to the nitrogen atoms in the basal plane of graphene leads to composite materials with superior activity and stability when used as counter electrodes in dye-sensitized solar cells (DSSCs). A series of composite materials based on different metals (Mn, Fe, Co, Ni, and Cu) were synthesized and characterized. Electrochemical measurements revealed that CoN4/GN is a highly active and stable counter electrode for the interconversion of the redox couple I-/I-3(-). DFT calculations revealed that the superior properties of CoN4/GN are due to the appropriate adsorption energy of iodine on the confined Co sites, leading to a good balance between adsorption and desorption processes. Its superior electrochemical performance was further confirmed by fabricating DSSCs with CoN4/GN electrodes, which displayed a better power conversion efficiency than the Pt counterpart.
- 出版日期2016-6-1
- 单位中国科学院; 催化基础国家重点实验室; 中国科学院大连化学物理研究所; 中国科学院上海应用物理研究所; 中国工程物理研究院