Three-dimensional activated porous carbon with meso/macropore structures derived from fallen pine cone flowers: A low-cost counter electrode material in dye-sensitized solar cells

Honeycomb-like activated porous carbon (HPC) powder with meso/macropore structures was successfully prepared via chemical activation and pyrolysis processes under inert gas atmosphere. Herein, the naturally available pine cone flowers with abundant carbon contents were employed as a biomass to synthesize the HPC sample. The structure and morphology of the HPC powder were characterized by various physicochemical techniques. Moreover, the as-prepared HPC sample was uniformly coated on fluorine doped tin oxide glass using a smooth brush and used as a cost-effective counter electrode (CE) in dye-sensitized solar cells (DSSCs). Under AM1.5G illumination, the fabricated DSSCs with HPC-based CE exhibited a high short-circuit current density (JSC) of 13.51 mA/cm2 and an excellent power conversion efficiency (PCE) of 4.98%, which is attributed to the high specific surface area and hierarchical porous property of the HPC sample. The obtained results were improved compared to the commercially available activated carbon-based CE in DSSCs (JSC = 12.11 mA/cm2 and PCE = 4.45%). This facile fabrication of highly porous activated carbon-based materials from the biomass can be utilized as a high-performance electrode material in DSSCs and energy storage device applications.