CoFe/CoFe 2 O 4 Embedded N, S‐Doped Carbon Hybrid Derived From Sulfonate Asphalt as an Efficient Counter Electrode for Quantum Dot Sensitized Solar Cell

Developing a sustainable and cost‐effective counter electrode (CE) material with high catalytic activity is of significant importance for quantum dot‐sensitized solar cells (QDSSCs). In this work, by using the industrial residue material of sulfonated asphalt as the carbon precursor, we prepared a CoFe/CoFe 2 O 4 embedded N, S‐doped carbon hybrid (CoFe/CoFe 2 O 4 @C) and applied to the CE of QDSSC. Structure analyses indicated that CoFe/CoFe 2 O 4 @C has a porous structure with large surface area. Electrochemical investigations revealed that the CoFe/CoFe 2 O 4 @C possesses high catalytic activity for polysulfide reduction. Consequently, CdSe QDSSC based on CoFe/CoFe 2 O 4 @C CE achieved a high power conversion efficiency (PCE) of 6.37%, significantly superior to the commonly used PbS CE (5.4%). This study provides a sustainable strategy for converting the industrial residue material of asphalt into a low‐cost and high‐performance CE material for QDSSC.