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 573K 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 18.3nm and carbon shell thickness of 3–5nm. Larger Cu nanoparticles having an average diameter of 24.5nm in TiO2 was formed when their carbon shells were steam reformed at 673K. 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.