▎ 摘　　要

The development of low cost electrocatalysts with excellent I-/I-3(-) redox reaction efficiency is critically important for practical applications of dye-sensitized solar cells (DSSCs). Nevertheless, it is difficult to simultaneously improve the activity and stability of catalysts. Herein, heterogeneous FeNi3/NiFe2O4 nanoparticles are successfully embedded in modified graphene (mGr) matrix with network structure. As-prepared FeNi3/NiFe2O4@mGr shows excellent electrocatalytic activities and high stability. The DSSCs with FeNi3/NiFe2O4@mGr as counter electrodes demonstrate a high power conversion efficiency of 12.14%, which is superior to that of platinum (Pt, 8.31%). Also, the FeNi3/NiFe2O4@mGr device remains 90% efficiency up to 42 days under ambient conditions without encapsulation. Therefore, the FeNi3/NiFe2O4@mGr composite can be further developed as an environmentally friendly, inexpensive, and efficient counter electrode material for DSSCs.