Enhancing the performance of dye-sensitized solar cells by benzoic acid modified TiO2 nanorod electrode

The anatase TiO2 nanorods capped by oleic acid with the length of 30–50 nm and diameter of approximately 4–5 nm were prepared by a facile two-phase hydrothermal method. The oleic acid ligands attached on the surface of TiO2 nanorods were completely exchanged by benzoic acid ligands. The dye-sensitized solar cell (DSSC) fabricated based on the benzoic acid modified TiO2 nanorod electrodes exhibited a higher power conversion efficiency of 6.37% than that (5.1%) of the P25 TiO2 based DSSC. The surface modification by benzoic acid can effectively improve the hydrophility of TiO2 nanorods, leading to an increased short circuit current density and a higher open circuit voltage. This study provided a facile alternative method to fabricate highly efficient TiO2 nanorod-based electrodes for DSSCs.

► Hydrophobic anatase TiO2 nanorods were prepared by a two-phase hydrothermal method.
► The enhanced hydrophibility of TiO2 NRs can be obtained by a ligand exchange process.
► A high power conversion efficiency of 6.37% can be gained by the TiO2 NRs based dye-sensitized solar cell (DSSC).