Effective Synthesis of Well-Graphitized Carbon Nanotubes on Bimetallic SBA-15 Template for Use as Counter Electrode in Dye-Sensitized Solar Cells

The fabrication of dye-sensitized solar cells (DSSCs) using well-graphitized carbon nanotubes (CNTs) as a counter electrode has been described in this study. The well-graphitized CNTs were synthesized at different temperatures (700, 800, and 900 degrees C) using bimetallic Fe-V catalyst supported on Santa Barbara Amorphous-15 (SBA-15). The molecular ratios between the two metals were varied in the catalytic template, and their effect on the distribution of the synthesized CNTs was studied. Cyclic voltammetry and electrochemical impedance spectroscopy revealed that the CNTs had higher electrochemical activity for the I-3(-)/I- redox reaction and a smaller charge transfer resistance than the platinum (Pt) electrode. Energy conversion efficiency of the CNTs was compared with Pt counter electrode. These results indicated that the CNTs have high surface conductivity, high active surface area, and good catalytic activity and can potentially replace Pt as counter electrode for application in DSSCs.