Cu@C dispersed TiO2 for dye-sensitized solar cell photoanodes

Nanosize copper embedded in the inert carbon shell (Cu@C) prepared by carbonization of Cu2+-β-CD at 573 K was dispersed in TiO2. The Cu@C (0.1% and 0.3%) dispersed TiO2 was used in assembling of photoanodes for dye-sensitized solar cells (DSSCs). By small angle X-ray scattering (SAXS) spectroscopy, it is found that the Cu@C dispersed TiO2 having an average Cu diameter of 18.3 nm and carbon shell thickness of 3–5 nm. Larger Cu nanoparticles having an average diameter of 24.5 nm in TiO2 was formed when their carbon shells were steam reformed at 673 K. The Cu nanoparticles having a spherical shape are well dispersed in TiO2, which significantly enhance the photo-excited electron transfer for the DSSC. Notably, the Cu dispersed TiO2 photoanode has a greater efficiency than the pure TiO2 one by at least 23%. This work exemplifies a simple and novel alternative to enhance DSSC efficiencies.

► The Cu nanoparticles are well dispersed in TiO2 after steam reforming.
► The nano-Cu dispersed TiO2 can enhance the electron transfer for DSSCs.
► The dye absorption in the Cu dispersed TiO2 is enhanced by 2–3 folds.