Synthesis of TiO2 Nanoparticles on Plasma-Treated Carbon Nanotubes and Its Application in Photoanodes of Dye-Sensitized Solar Cells

Carbon nanotubes (CNTs) have attracted much interest because of their special physicochemical properties. Herein, O2 plasma-treated CNTs (denoted as PS-CNTs) are incorporated within a TiO2 matrix (denoted as PS-CNTs/TiO2) as photoanodes in dye-sensitized solar cells (DSSCs). The PS-CNTs/TiO2 composites provide more uniform holes and rough surface over the photoanode and also provide a greater degree of dye adsorption and lower levels of charge recombination, as compared to either chemical modified CNTs/TiO2 (denoted as CM-CNTs/TiO2) or TiO2 alone. The high dispersion of TiO2 on PS-CNTs can improve the electron conduction paths, leads to high electron transfer efficiency, and thereby results in the high performance of the DSSC devices. Herein, the PS-CNTs/TiO2-based working photoanode demonstrates a conversion efficiency of 6.34% in DSSCs, which is ∼75% higher than that of conventional TiO2-based devices.