Preparation and Photoelectrochemical Performance of Potassium Hexatitanate Nanoflim

Nanostructured K2Ti6O13 film photoelectrode produced in situ was prepared on indium-tin oxide (ITO) glass substrate by a sol-gel process and characterized by thermogravimetry (TG) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Visible diffuse reflectance and Raman spectrometry. The photoelectrochemical performance of K2Ti6O13 film was assessed by eleetrochemical method. The analytical results showed that the K2Ti6O13 film had a strong and wide absorption in the ultraviolet and visible light range. The band gap energy (E(subscript g)) of the film shifted from 3.45 eV (bulk) to 3.05 eV (film). The flat-band potential (E(subscript fb)) of K2Ti6O13 film was -0.67 V [vs. saturated calomel electrode (SCE)]. The transport of photogenerated electrons and holes was better in K2Ti6O13 film electrode than that in TiO2 film electrode. The photoelectrochemical response of K2Ti6O13 photoelectrode was increased in electrolyte solution with KOH, compared with that in the solution without KOH. The adsorption of OH(superscript -) on the nanofilm acted as the surface activity center. The mechanism of photolysis was analyzed in terms of photoelectrochemical behavior.