Effect of TiO₂ Nanotube Arrays Morphology/Structure on Photocatalytic Hydrogen Production

To provide clean energies, great efforts have been contributed to hydrogen production via photocatalytic water splitting over the past decades. Among many potential materials, TiO₂ nanotube array has been considered as one of the most attractive photoanodes due to its advantages, such as low cost, non-toxicity and chemical stability. It has been discovered that TiO₂ nanotube arrays (TNTs)' photocatalytic performance was dictated by their morphologies, which is mainly controlled by the outer voltage. In order to further understand the effect of TNTs' morphologies on their photocatalytic capability, TNTs with different structures had been fabricated under different voltage (10, 20, 30, 40 and 50 V). The obtained TNTs' morphologies and phase were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction analyzer (XRD). The photocatalytic properties of TNTs were investigated in aqueous solution under xenon lamp irradiation. It was identified that the highest hydrogen production of the sample synthesized at the voltage of 30 V was 1979.8 μmol/h·g during the first cycle.