Surface treated TiO_2 nanorod arrays for the improvement of water splitting

摘要

Water splitting is widely employed for the hydrogen production for its abundant sources of water and sunlight. The TiO_2 nanostructures are the most promising materials because of their properties of the non-toxicity and relatively low cost. Surface treatments with TiCl_4 solution and titanium butoxide solution are applied on the TiO_2 nanorod arrays respectively. On the surface of the TiO_2 nanorods, TiO_2 nanoparticles are prepared through hydrolysis of TiCl_4 and homogeneous phase of TiO_2 synthesized with assist of second hydrothermal synthesis in titanium butoxide, resulting in the increase of the surface area of the TiO_2. Comparing with that of the original TiO_2 nanorod arrays, the incident photon-to-electron conversion efficiency (IPCE) of the TiO_2-TiCl_4 and TiO_2-H_2O samples is greatly enhanced by 25% and 250% in the ultraviolet region, respectively. The obviously enhanced activity is due to the larger surface structure after treatments, which could contribute to the improved performance in the water splitting. These surface treatments provide an efficient way to regulate the properties of the TiO_2 nanorod arrays for their extensive applications in the solar device for the hydrogen production.