Glucose-derived porous carbon as a highly efficient and low-cost counter electrode for quantum dot-sensitized solar cells

Biomass-derived porous carbon is widely used in supercapacitors, carbon dioxide capture and lithium-sulfur batteries owing to its advantages such as wide sources, low cost and good stability. However, it is rarely used in quantum dot-sensitized solar cells (QDSCs). Here, glucose-derived porous carbon was obtained by hydrothermal carbonization followed with high-temperature KOH activation, and employed as an efficient counter electrode (CE) for QDSCs. The CV, EIS and Tafel-polarization analysis showed that porous carbon exhibits excellent catalytic activity for reduction of S-n(2-). The CE based on porous carbon activated at 900 degrees C (C-900) presents best performance with interface charge transfer resistance (R-ct) of 2.4 omega cm(2) due to the synergy between high graphitization degree and large specific surface area. The power conversion efficiency (PCE) of the QDSCs assembled with a CdS/CdSe sensitized TiO2 photoanode and the C-900 CE is up to 5.61% under one sun illumination. The excellent catalytic activity of C-900 is attributed to its large specific surface area and porous structure and high degree graphitization. This suggests that glucose-derived porous carbon can become a potential low-cost and efficient CE material for QDSCs.