Preparation And Properties Of Defective Mesoporous Titanium Dioxide Nanotube-Based Photocatalysts

One-dimensional titanium dioxide（1D TiO₂）nanotubes have high specific surface area,abundant surface active sites and short photo-generated carrier transport distance,showing good photocatalytic performance,and are also excellent hosts for the construction of composite materials.However,TiO₂ has significant problems,such as wide band gap and absorption of ultraviolet light,which affects the utilization rate of sunlight.The low efficiency of photocharge separation also greatly affects the photocatalytic performance.In order to solve the obvious problems of TiO₂,we prepared defective 1D mesoporous anatase TiO₂ nanotubes by solvo-thermal bonding with high temperature surface hydrogenation.After surface hydrogenation,the band gap of TiO₂ nanotubes is narrowed,and the light response range is extended to the visible region.It can be used as a host to construct a composite material to further improve the efficiency of photoelectric charge separation and thus improve the photocatalytic performance.In this paper,the synthesis of defective mesoporous TiO₂ nanotubes and their complexes and the comparison with their photocatalytic performance were studied to solve the above problems.In this regard,the following three aspects were described:1.1D mesoporous anatase TiO₂ nanotubes（H-TiO₂）with surface defects were prepared by solvothermal and high temperature surface hydrogenation.H-TiO₂ showed excellent hydrogen production performance(9.8 mmol h^-1 g^-1),which was about 2.5times higher than that of the original white Air-TiO₂ nanotubes(3.8 mmol h^-1 g^-1).This excellent performance is attributed to the rapid electron transport channel of 1D nanotube materials and the abundant surface active sites provided by the mesoporous structures with large specific surface area.2.Boron doped defective mesoporous TiO₂ nanotubes（B-TiO₂）with surface defects were prepared by thermal reduction at high temperature.B doped 1D TiO₂3.nanotubes showed excellent photocatalytic hydrogen production performance(17.4 mmol h^-1 g^-1),which was more than 4.5 times that of Air-TiO₂(3.8 mmol h^-1 g^-1)and nearly 1.8 times that of H-TiO₂(9.8 mmol h^-1 g^-1).4.NiO nanoparticles/B-doped defective mesoporous TiO₂ nanotube complex（NiO/B-TiO₂）was synthesized by stirring and ultrasonic wet impregnation using B-TiO₂as host.NiO/B-TiO₂ has good photocatalytic hydrogen production performance(24.1mmol h^-1 g^-1),which is nearly 1.4 times higher than that of B-TiO₂(17.4 mmol h^-1 g^-1).This new synthesis strategy provides a new idea for the development of novel photocatalytic composites and has potential application prospects in the field of clean energy.