Bifunctional Nanostructured TiO2 photoelectrocatalyst for Improving Overall Water splitting performance
Titanium dioxide TiO2 is a semiconductor, that has great chemical and physical properties, such as remarkable resistance against corrosion, chemical stability, and it’s a non-toxic material. Due to these properties, it rises as an excellent candidate for a wide range of different applications, such as being a popular material for solar cells, paints, cosmetics, energy storge devices, and water splitting. For photoelectrochemical water splitting to generate Hydrogen, a large surface area is essential, to be maximized to enhance photocatalytic redox processes and hence improve overall efficiency. Therefore, different methods have been utilized to fabricate TiO2 nanotubular structure. However, they either encounter a difficult process because of a long synthesis time or the need of expensive precursors. In our work, we demonstrated a study of enhancing 1 D TiO2 film to perform as a bifunctional catalyst (works as cathode and anode). As it is known that TiO2 is kinetically hampered as cathode for producing hydrogen from water, this is due to sluggish electron transfer at the interface between TiO2 and water and the conduction band of the TiO2, which is more negative than H+/H2. To tackle this problem, TiO2 film should be modified. In this work, we modified the TiO2 as bifunctional by investigating different parameters in detail, like the anodic oxidation solution content, anodic oxidation time, and the role of the polyethylene glycol chain. Electrochemical characterization and SEM, and XPS were utilized to prevent the nanotubes structure and to confirm the chemical bonding as well as investigating the physical properties such as resistance and electron kinetic mobility.