An efficient photocatalyst used in a continuous flow system for hydrogen evolution from water: TiO2 nanotube arrays fabricated on Ti meshes

Abstract

In the present work, TiO₂ nanotube arrays were fabricated on metallic Ti meshes using anodic oxidation method, and decorated with Pt via electrodeposition. Meanwhile, the application of the TiO₂ nanotube arrays loaded with Pt in a continuous flow system was explored as a photocatalyst for H₂ evolution from water. Furthermore, for practical purposes, the photocatalytic H₂ evolution was studied as a function of content of loaded Pt, annealing temperature, anodic oxidation time, and flow velocity. The results indicate that the TiO₂ nanotube arrays fabricated on metallic Ti meshes are an efficient photocatalyst which can be used in a continuous flow system for H₂ evolution from water. During the first hour of irradiation, a rate of H₂ evolution of approximately 4.6 L m⁻² h⁻¹ was achieved under optimal conditions. Moreover, the photocatalytic activity of the TiO₂ nanotube arrays fabricated on Ti meshes is obviously higher than that of the TiO₂ nanotube arrays fabricated on metallic Ti foils. The rate of H₂ evolution can increase by a factor of 5 when the TiO₂ nanotube arrays are fabricated on metallic Ti meshes. Finally, the photocatalytic mechanism was preliminarily discussed.