Preparation of Heteromorphic Ni Decorated Fe‐Containing Carbon Nanofibers as Efficient and Low‐Cost Counter Electrodes for Dye‐Sensitized Solar Cells

In the field of dye-sensitized solar cells (DSSCs), although Pt is commonly used as counter electrode materials owing to its great electrocatalytic activity and conductivity, the high price and small reserves of Pt limit its large-scale application. In this paper, heteromorphic Ni decorated Fe-containing carbon nanofibers (Ni/NiO@Fe-CNFs) was prepared by a thermal synthesis method, and applied as composite counter electrode materials for DSSCs. It was found that the as-synthesized Ni/NiO@Fe-CNFs shows better electrocatalytic activity than that of Fe-CNFs and CNFs for the reduction reaction of triiodide to iodide. The improved electrocatalytic activity is not only attributed to the introduction of Fe2O3 to form Fe-CNFs, but also attributed to the heteromorphic Ni decoration and their synergistic effect. The photoelectric conversion efficiency of DSSCs with Ni/NiO@Fe-CNFs counter electrode is 4.81 %, much higher than that of CNFs (0.62 %) and Fe-CNFs counter electrode (3.65 %), and comparable to the value of Pt counter electrode (5.10 %). Accordingly, the Ni/NiO@Fe-CNFs is expected to be a potential counter electrode material to replace Pt.