The Research Of Ronidazole Photocatalytic Degradation By Noble Metals ?Ag Pt Pd? As Well As Its Metallic Oxides Modified Ga₂O₃

Photocatalysis is a kind of advanced oxidation technologies with the advantages of high-efficiency and no secondary pollution.It has been widely used in the degradation of many kinds of organic contaminant.Ga₂O₃ is a newly emerging photocatalyst that has a promising application in organic pollutant degradation.But the recombination of the photogenerated electrons and holes of Ga₂O₃ will be the limitation of its application,so it's meaningful to enhance its photocatalytic activity.According to research,various modifications have been carried out to enhance the photocatalytic activity of photocatalysts,such as:surface modification by noble metals,coupling with other narrow band gap semiconductors or doping with other metal ions.But relevant reports of these kinds of methods applied in Ga₂O₃ modification are less.In addition,different preparation methods will change the form of metals,thus result in different photocatalytic activity of modified Ga₂O₃.In this research,we used AgNO₃?H₂PtCl₆ and PdCl₂ as the source of metals,photoreduction and chemical deposition technologies were used to prepare noble metal modified Ga₂O₃ and metallic oxides modified Ga₂O₃,respectively.Then,compared different influence on the photocatalytic activity with two kinds of modified methods as well as the form of metals,and analysis the mechanism of the impact.Ronidazole,which is a typical nitroimidazole antibiotic,was used to evaluate photocatalytic activities of the synthesized photocatalysts.It's meaningful for the removal of nitroimidazole antibiotic.The main conclusions of this paper are listed as follows:?1?Photodeposition technology was used to synthesized noble metals modified Ga₂O₃.Characterization shows that the crystalline phase and crystal structure had no change after modification.Most of the noble metal particles were in nanoscal with the size of 20?200 nm.The Light adsorption ability of Ga₂O₃ was enhanced significantly after modified Ag?Pt and Pd,and the light response scope was been broadened as well.The energy bands of modified Ga₂O₃ were slightly decreased,with 4.1 eV of Ag-Ga₂O₃ and Pd-Ga₂O₃ and 3.8 eV of Pt-Ga₂O₃.?2?The photocatalytic activity of noble metal modified Ga₂O₃ was evaluated by ronidazole degradation.The degradation rate of ronidazole by Ag-Ga₂O₃?Pd-Ga₂O₃ and Pt-Ga₂O₃ was 92.3%?89.9%and 38.0%,respectively.The difference of noble metal modified Ga₂O₃ was related to the electron affinity of noble metals and Ga₂O₃.?3?Chemical deposition technology was used to synthesized metallic oxides modified Ga₂O₃.Characterization shows that the crystalline phase and crystal structure had no change after modification,and the sizes of metallic oxides were smaller than the noble metals.The Light adsorption ability of Ga₂O₃ was enhanced significantly after loaded Ag₂O and PdO.The band energy of Ag₂O-Ga₂O₃ was 3.76 eV while the PdO-Ga₂O₃ was 3.6 eV.But the light adsorption ability and band energy of Ga₂O₃ had no influence after loaded PtO₂.?4?The photocatalytic activity of metallic oxides modified Ga₂O₃ was evaluated by ronidazole degradation.The degradation rate of ronidazole by PtO₂-Ga₂O₃ and Ag₂O-Ga₂O₃ was 88.2%and 82.5%respectively,which were enhanced the photocatalytic activities of Ga₂O₃.But the photocatalytic activity was decreased after loaded PdO,with 17.4%degradation rate of ronidazole.The difference by Ag2O-Ga₂O₃?PtO2-Ga₂O₃ and PdO-Ga₂O₃ on ronidazole degradation is because of the different band energy of metallic oxides and Ga₂O₃.