Screen-Printed Alkalized Ti₃C₂T_x MXene–PEDOT Nanofibers as Alternative Photocathodes for Dye Sensitized Solar Cells

The advancement of dye-sensitized solar cells (DSSCs) critically hinges on the innovation of cost-effective, high-performance counter electrode (CE) catalysts. This research outlines a synthesis route for fabricating platinum (Pt)-free CE catalysts, specifically alkalized Ti₃C₂T_x MXene–PEDOT nanofibers (a-Ti₃C₂T_x-PNFs). The synthesis methodology entails the alkalization of acid-etched Ti₃C₂T_x using KOH, followed by intercalation with PEDOT nanofibers. The formation of the hybrid a-Ti₃C₂T_x-PNFs was confirmed through an array of characterization techniques, including XRD, XPS, HRSEM, and HRTEM. Electrochemical evaluations revealed that the a-Ti₃C₂T_x-PNF hybrid exhibits exceptional catalytic reduction capabilities and demonstrates a remarkably low charge-transfer resistance of 8.5 Ω cm² for the reduction of triiodide electrolyte. Consequently, DSSCs incorporating the a-Ti₃C₂T_x-PNF CE achieved a power conversion efficiency (PCE) of 7.1% under optimized conditions, closely approaching the 8.06% efficiency observed with Pt-based CEs. Moreover, the reproducibility and stability tests confirmed that the a-Ti₃C₂T_x-PNF CE offers consistent performance and high corrosion resistance in iodide/triiodide electrolyte. These findings emphasize the possibility of using a-Ti₃C₂T_x-PNFs as a practical substitute for platinum in high-performance DSSCs, representing a notable advancement in the progress of contemporary solar cell technology.