Transparent TiO2Photoanodes Based on Single Walled Carbon Nanotubes

Transparent titania (TiO 2 ) photoanodes deposited on single walled carbon nanotubes (SWCNT) films obtained by drop casting (TD) and filtration (TF) were characterized in various electrolytes. Improved photoelectrochemical performance was observed in the two types of transparent photoelectrodes relative to those without SWCNT. For both SWCNT deposition methods, the best photoanode performance corresponds to SWCNT films with 75–85% optical transmittance (T). Overall, there is a 50–60% increment in photovoltage caused by the addition of SWCNT. For photoanodes with 85%T, the SWCNT fabrication method has little impact on photocurrent, fill factor, and flatband potential. Characteristic times (τ), on the other hand, are similar in TiO 2 and in photoanodes based on filtrated-SWCNT films, but a factor of 3 to 6 larger on those fabricated on casted-SWCNT (τ = 1–2 s). Differences between τ(TF) and τ(TD) indicate different trapping/detrapping dynamics within the SWCNT-TiO 2 electrodes, which could originate from the different Fermi levels observed in the SWCNT-TiO 2 electrodes.