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+-beta-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. (C) 2012 Elsevier Ltd. All rights reserved.