Preparation And Performance Of Nonmetallic Modified TiO₂ Nanobelts

Over the past two decades,1D TiO₂ nanostructure materials,with various morphologies including nanobelts,nanowires and nanotubes,have attracted great attention in solar energy conversion,photocatalysis,gas sensing,biomedicine,and environmental monitoring due to its exceptional electric,high regulation,highly recycle efficiency and excellent controllability.Inertness to chemical environment and long-term photostability have made TiO₂ an important component in many practical applications and commercial products.From drugs to doughnuts,cosmetics to catalysts,paints to pharmaceuticals,and sunscreens to solar cells,TiO₂ is used as a desiccant,brightener,or reactive mediator.In addition,due to its larger pore volume,larger specific surface area and,1D TiO₂ nanometer material can be used as a kind of very good photocatalytic material.However,one of the critical drawbacks of TiO₂ photocatalyst is a wide band gap which restricts the excitation to UV light irradiation and greatly decreases the utilization of sunlight due to a small ultraviolet fraction of the solar spectrum,what's more,the photo-generated electrons and holes could recombine rapidly again.So nonmetallic doping and coupling TiO₂ with a splendid visible light semiconductor photocatalyst are effective way to enhance the visible light photocatalytic activity.According to previous research,we prepared TiO₂ nanobelts and coarsened TiO₂ nanobelts via hydrothermal method and characterized its related characterization and photocatalytic activity.In the aspect of modification,we doped TiO₂ nanobelts with nonmetallic S via hydrothermal method.In addition,p-n junctions consisting of BiOI/TiO₂ nanobelts and BiOI/coarsened TiO₂ nanobelts,which contain a typical heterostructure were synthesized with the same purpose of enhancing the visible light photocatalytic activity.The research work and conclusions are as follows:?1?We prepared H₂Ti₃O₇ nanobelts,TiO₂ nanobelts and coarsened TiO₂ nanobelts via hydrothermal method by dispersing commercial P25 into 10 M NaOH solution.The surface coarsened TiO₂ nanobelts were obtained by acid treatment of H2SO4 via hydrothermal method.The visible light photocatalytic activity of TiO₂ nanobelts and coarsened TiO₂ nanobelts were tested by degrading MO solution.?2?Under the preparation conditions of TiO₂ nanobelts above,S-doped TiO₂ nanobelts were prepared through hydrothermal method.Furthermore,we investigated the structure,morphology and photocatalytic activity of the doped samples.The results indicated that doped TiO₂ nanobelts possess a better photocatalytic activity than pure TiO₂ nanobelts.?3?The novel photocatalysts of BiOI nanosheet/TiO₂ nanobelt heterojunctions and BiOI nanosheet/coarsened TiO₂ nanobelt heterojunctions were prepared by the same hydrothermal method mentioned above.BiOI nanosheets attached on the surface of TiO₂ nanobelts or coarsened nanobelts forming abundant special heterojunctions.The photocatalytic activity results of the modified BiOI/TiO₂ system showed that BiOI nanosheet/coarsened TiO₂ nanobelt heterojunctions have the best photocatalytic activity with the BiOI to TiO₂ mole ratios at 1:1.The possible mechanism of promoting photocatalytic performance of the new heterostructure system is explained.