Anodic TiO2 nanotubes powder and its application in dye-sensitized solar cells

An increasing energy demand and environmental pollution create a pressing need for clean and sustainable energy solutions. TiO2 semiconductor material is expected to play an important role in helping solve the energy crisis through effective utilization of solar energy based on photovoltaic devices. Dye-sensitized solar cells (DSSCs) are potentially lower cost alternative to inorganic silicon-based photovoltaic cells. In this study, we report on the fabrication of DSSCs from anodic TiO2 nanotubes (NT) powder, produced by rapid breakdown potentiostatic anodization of Ti foil in 0.1 M HClO4 electrolyte, as photoanode. TiO2 NT powders with a typical NT outer diameter of approximately 40 nm, wall thickness of approximately 8–15 nm, and length of about 20–25 μm, have been synthesized. The counter electrode was made by electrodeposition of Pt from an aqueous solution of 5 mM H2PtCl6 onto fluorine-doped tin oxide (FTO) glass substrate. The above front-side illuminated DSSCs were compared with back-side illuminated DSSCs fabricated from anodic TiO2 NTs that were grown on the top of Ti foil as photoanode. The highest cell efficiency was 3.54% under 100 mW/cm2 light intensity (1 sun AM 1.5G light, Jsc = 14.3 mA/cm2, Voc = 0.544 V, FF = 0.455). To the best of our knowledge, this is the first report on the fabrication of DSSC from anodic TiO2 NTs powder. The TiO2/FTO photoanodes were characterized by FE-SEM, XRD, and UV–Visible spectroscopy. The catalytic properties of Pt/FTO counter electrodes have been examined by cyclic voltammetry.