Hydrogenation of Nano-Structured TiO2 Photocatalyst Through an Electrochemical Method.

Nano-structured photocatalyst P25 was electrochemically hydrogenated through being immersed in 0.01 M NaOH solution to act as cathode to electrolyze water. With its color changed from white to bluish, its absorption in visible light range was obviously enhanced after the treatment, and its solar-driven photocatalytic activity was significantly improved for photo-degradation of methylene blue and rhodamine B. XPS spectra analyses were conducted and the photocurrent was measured, which indicate the formation of Ti3+ and oxygen vacancies, and increased separation efficiency of photoactivated electrons and holes in electrochemically hydrogenated P25. These changes are proposed responsible for the improved photocatalytic activity of P25. Electrochemical hydrogenation has been proven a facile and effective method for improving the photocatalytic activity of nano-structured TiO2 photocatalyst.