Design highly effective B or N doped mesoporous carbon fibers catalysts for I3-/I- redox couple regeneration in carbon-based dye-sensitized solar cells

Construction of mesoporous structure and improving the conductivity of carbon counter electrode are feasible paths to enhance the catalytic activity in dye-sensitized solar cells (DSCs) toward the I 3 - /I - redox couple regenerating (IRR). Herein, mesoporous carbon fiber (PCf) has been first synthesized and the DSCs using PCf counter electrode results in a power conversion efficiency (PCE) of 7.12%, significantly surpassing the PCE of 6.01% generated by the DSCs with carbon fiber (Cf) counter electrode without mesoporous structure. Additionally, doping with heteroatoms B or N can further enhance the catalytic performance of PCf. Consequently, B or N doped Cf (BPCf or NPCf) counter electrode-based DSCs achieve high PCE values of 8.43% and 7.96%, respectively, demonstrating PCE improvements of 40.3% and 32.4%. This enhancement in catalytic activity for IRR in DSCs can be first attributed to the increased specific surface area of Cf which can provide more catalytic activated sites. Meanwhile, the enhanced conductivity of PCf by heteroatoms B or N doping is also an important factor for the improved catalytic activity. This work is expected to provide potential path to enhanced the catalytic activity of carbon counter electrode in DSCs toward IRR.