Activated carbon of lokta paper for low-cost counter electrodes of dye-sensitized solar cells

Carbon, synthesized by carbonization of Zncl2 activated Lokta paper at 800 degrees C, was investigated as a counter electrode (CE) material to replace platinum in dye-sensitized solar cells (DSCs). Structural and elemental composition of the activated carbon were analyzed with x-ray diffraction, Raman spectroscopy, and Energy dispersive x-ray spectroscopy. N2 adsorption-desorption experiment revealed porous surface of the sample with total pore volume of 0.9042 ccg-1. Brunauer-Emmett-Teller surface area of the carbon was 1372 m2g-1. The ability of the activated carbon of transferring electrons to the tri-iodide ions in the electrolyte at the catalyst-electrolyte interface was evaluated by electrochemical impedance spectroscopy of symmetrical dummy cells. Charge transfer resistance of the activated carbon coated electrode was comparable to that of platinum coated electrode indicating comparable catalytic ability of the carbon to platinum. Efficiency of the DSCs with the activated carbon and platinum were 5.12% and 5.58%, respectively. Comparable efficiencies of the solar cells indicate applicability of the Lokta-based activated carbon as an efficient and low-cost CE material.