Preparation Of One-dimensional Gallium Oxide Nanomaterials And Their Application In Photodegrading Organic Dyes

Environmental pollution,especially water pollution,which is related to the survival of humankind and natural creatures,has been attached many attentions in recent years.In water pollution,many organic macromolecular pollutants are difficult to filter and separate,toxic to microorganisms,and have a long natural degradation time,which can be removed with the help of advanced catalytic oxidation technology.As one of the most widely studied advanced catalytic oxidation technologies,the photocatalytic oxidation technology bases on the photo-excitation effect of semiconductor materials to achieve the catalytic degradation of organic pollutants.Wide bandgap semiconductor oxides have attracted many attentions of researchers due to their wide bandgap and high stability.Compared with other common oxide semiconductor photocatalysts,such as TiO₂,ZnO,and SnO₂,Ga₂O₃ has gradually shown its unique advantages in the field of photocatalysis due to their ultra-wide band gap（4.4-4.9 eV）.As we all known,the photocatalytic process based on semiconductor materials mainly depends on the photo-generated carriers,and the energy of the photo-generated carriers depends on their energy level position.So the catalytic oxidation/reduction ability of the semiconductor material is related to the energy band position.Compared with the position of standard hydrogen reduction potential,the lower valence band position of the Ga₂O₃ make the holes in it have stronger oxidizing ability.Therefore,it can be seen that Ga₂O₃ materials should have a stronger ability to degrade organic pollutants compared with other wide band gap semiconductors.However,because Ga₂O₃ material is a direct band gap semiconductor,the recombination rate of photogenerated electron-hole is high,which greatly hinders the practical application of Ga₂O₃ photocatalyst.In order to solve this problem,many efforts including ion doping and construction of composite structure have been done to improve the electron-hole separation efficiency of Ga₂O₃ materials in this thesis,The research content of this article is as follows:（1）Ga₂O₃ nanofibers were prepared by electrospinning method and post-annealed treatment.The morphology and phase of the samples were analyzed by SEM,XRD,and XPS.The photocatalytic properties of the samples were tested.In order to clear the influence of annealing temperature for the photocatalytic performance,the obtained Ga₂O₃ nanofibers were annealed at different temperatures.（2）Zn-doped Ga₂O₃ samples were prepared by electrospinning method with the addition of Zn ion in the precursor solution.The morphology characterization and phase analysis were carried out,and its photodegradation ability was tested.The influence of Zn doping concentration on the catalytic properties of Ga₂O₃ has been studied.The internal photocatalytic mechanism was analyzed based on the test results.（3）Ga₂O₃ samples added different amounts SiO₂ nanosphere were prepared.The morphology and phase of the samples were analyzed,and the photodegradation performance of each sample was tested to study the influence of the addition of SiO₂nanospheres on the physical properties and photocatalytic performance of Ga₂O₃..（4）SiO₂/Ga₂O₃ hybrid samples were also prepared by the electrospinning method with the addition of different TEOS amount.The morphology and phase analysis of the samples were carried out.Afterwards,the photocatalytic degradation performance of each sample was tested and analyzed to study the influence of TEOS on the physical properties and photocatalytic performance of Ga₂O₃.