▎ 摘　　要

We report on the effect of graphene (G) incorporation in TiO2 photoanodes (PAs) for improv ing their dye adsorption capacity, which in turn impacts the overall photoconversion efficiency of dye-sensitized solar cells (DSSCs). By varying the graphene content of TiO2 PAs (over the 0.05-1 wt.% range), the power conversion efficiency (PCE) of the DSSCs was found to increase significantly from 3.0% for standard TiO2 to a maximum value of 8.2% for PAs containing 0.1 wt. % of graphene. This corresponds to a PCE improvement of similar to 173% in comparison with standard DSSCs made with TiO2 alone (without graphene). On the other hand, by performing thermogravimetric analyses to quantify the dye adsorption capacity of the TiO2-G PAs, we were able to establish, for the first time, a direct correlation between the PCE of the DSSCs and the dye uptake of their G-TiO2-based PAs. Our results demonstrate that by coupling the optimal PA (with the optimal graphene content of 0.1 wt.% and optimal sensitization with a solution of 4 mM of N719) with Co-Ni nanoparticles decorated multi-walled carbon nanotubes (MWCNTs) based counter electrodes, we we re a ble to achieve DSSCs exhibiting a PCE as high as 9.8%. This performance is quite impressive particularly considering that no platinum was used in the counter electrode.