A COMPARATIVE STUDY OF GRAPHENATED-CARBON NANOTUBES COTTON AND CARBON NANOTUBES AS CATALYSTS FOR COUNTER ELECTRODE IN DYE-SENSITIZED SOLAR CELLS
This work reports a comparative study of synthesized graphenated-carbon nanotubes cotton (g-CNTC), standard carbon nanotubes (CNTP), and conventional platinum (Pt) thin layer which are employed as the counter electrodes in dye-sensitized solar cells (DSSC). The g-CNTC was synthesized via the floating-catalyst chemical vapor deposition (FCCVD) method. Subsequently, the g-CNTC was made into a uniform paste and deposited for the counter electrode layer. The results obtained from FESEM/TEM, Raman spectroscopy, CV and I-V measurements respectively exposed the structural, graphitization and I-V characteristics. Briefly, the morphology of g-CNTC showed the growth of graphene foliates out-sidewalls of CNT with a diameter of 40 nm. The graphitization of g-CNTC showed two dominant peaks namely the D (1355 cm-1) and G (1608 cm-1) bands with strong intensities. The g-CNTC counter electrode provided good electrical conductivity (3.66×10-3 to 6.45×10-3 S/cm), which is a significant feature to employ counter electrodes to enhance DSSC performance. In addition, the g-CNTC counter electrode offered an excellent catalytic activity for iodide/triiodide reaction and exhibited 3.49 % of photovoltaic conversion energy, which was much higher compared to CNTP (2.93 %) and platinum (3.12 %), respectively.