Controllable Synthesis And Photocatalytic Performance Of Vanadate-based Heterostructures

Photocatalysis,as one of the most advanced technologies,has attracted much attention of the researchers around the world in recent years.It employ the sunlight as driven force for the degradation of organic pollutants,water splitting and photoelectric conversion.Due to the environmental friendliness,photocatalysis is a promising technique to solve the problems of environmental pollution and energy crisis.Developing of an execllent visible-light photocatalyst is the crux of improving solar energy utilization ratio.For example,vanadates have drawn much attention because of their narrow band gap and high photocatalytic properties.In addition,the photocatalytic property and reusability of vanadates can be enhanced by constructing heterostructure and controlling morphology.In this paper,several vanadate-based heterostructured photocatalyst with one-dimensional morphologies have been synthesized by electrospinning,and their photocatalytic activities were also evaluated by the degradation of dyes solution under light irradiation.The main research contents as follows:1.InVO₄/BiVO₄ heterostructured photocatalysts were prepared by a simple electrospinning technique.As-prepared samples present one-dimensional porous nanobelts morphologies.The porous structure is advantageous to increase specific surface area and facilitate the transport of reactants and products.Meanwhile,the heterojunction can promote the separation of photogenerated electron-hole pairs.The results demonstrated that In VO₄/BiVO₄ heterostructured nanobelts exhibit the higher photocatalytic activity and sustainable circulation efficiency due to its special one-dimensional structure.2.TiO₂/Bi VO₄ porous nanofibers have been successfully synthesized for the first time via electrospinning.As-prepared products were composed by rutile TiO₂ and monoclinic BiVO₄.In addition,hydrothermal was carry out to crystallize Bi VO₄Quantum tube,which could inhibite the agglomeration and growth of BiVO₄ in the calcination process.The TiO₂/BiVO₄ multilevel structured nanofibers which prepared by two-step method were composed by anatase TiO₂,rutile TiO₂ and monoclinic Bi VO₄.The results indicated that the active groups in the photocatalytic reaction are h⁺and·OH.3.One-dimensional Fe VO₄ nanobelts with the width of about 400 nm were prepared by a simple electrospinning process.The morphologies,crystallite size and surface area of Fe VO₄ nanobelts were distinctly affected by the calcination temperature.And the samples calcined at 600°C owned an excellent photocatalytic properties.In addition,the lattice constants of FeVO₄ were decreased after doping a bit of P element,and the 0.5%P-doped FeVO₄ nanobelts presented an enhanced photocatalytic property owing to its lower recombination rate of photogenerated electro-hole pairs and the faster charge transport characteristic.4.Fe₂O₃/FeVO₄ heterogeneous nanobelts have been successfully prepared based on the formation process of FeVO₄ nanobelts.In the present electrospinning process,the differences of surface tension and conductivity between ethanol and DMF lead to the component gradient distribution in the nanobelts.Parts of Fe uniting with V are crystallized into FeVO₄ in the core,and the superfluous Fe form Fe₂O₃ as the shell and the analogous core-shell morphology which is similar to the leaves of bryophyllum pinnatum were achieved.The Fe₂O₃/FeVO₄ heterogeneous nanobelts possess great advantage on the applications in the future due to the excellent photocatalytic property and efficient recycling.