Effect of calcined temperature on photoelectrochemical and photocatalytic properties of K₂Ti₆O₁₃ thin films

The potassium hexatitanate thin films on ITO glasses substrates were prepared by sol-gel method, and was calcined at different temperatures. The structure and surface morphology of the K₂Ti₆O₁₃ film were examined by XRD and AFM, respectively. The photocatalytic activity of the K₂Ti₆O₁₃ film was evaluated by the degradation of partial coverage of octadecyltrichlorosilane (OTS) grafted on K₂Ti₆O₁₃ film, and the behaviour of photogenerated carrier was characterized by chronopotentiometry, cyclic voltammetry and chronoamperometry. The results show that the K₂Ti₆O₁₃ film calcined at 500°C has the highest photocatalytic activity and the highest photocurrent, it is even superior to TiO₂. The reason that K₂Ti₆O₁₃ film calcined at 500°C has the higher performance may be appropriate crystallinity, lesser grain size and large specific surface area, and the quantum yield illuminated under 254 nm laser source is 6.9%.