Low-Temperature Solution Synthesis And Photocatalytic Performances Of Aurivillius Bi₂MO_6-nF_n（M=Ti,Nb;n=2,1）and Their Composites

In recent years,environmental problems have become increasingly prominent.Solving environmental problems,whether for humanistic care or objective need,has being the highest voice of the society.As an important part of environmental problems,water pollution has always been widely concerned.It’s a good idea to eliminate water pollution back to its origin.While,it is often the responsibility of government workers.As a scientific researcher,it is often solved after the emergence of problems.At present,it is an effective way to solve the problem of water pollution.By using semiconductor as photocatalyst to degrade organic pollutants in water.The method is generally simple to operate,easy to obtain source,and it’s cheap,and low in energy consumption.Aurivillius-type compounds are typical bismuth layered semiconductors.It doesn’t have a further study at present,while researches on Aurivillius type oxfluorides is very little.The traditional methods to prepare of the Aurivillius oxyfluorides are often high temperature process and high energy consumption.And most of as-prepared products are not pure.Their morphology is messy.Thus,it becomes difficult to study further.The main contents of this paper are as follows:（1）A facil low-temperature solvothemal method to prepare pure Bi₂Ti O₄F₂ and Bi₂NbO₅F,Aurivillius type oxfluorides,with bismuth oxide as bismuth source,ethylene glycol solution（EG:H₂O=3:1）as dispersion solvent was proposed.The photocatalysts were characterized by X-ray powder diffraction（XRD）,field emission scanning electron microscopy（FESEM）,etc.The photocatalytic performances of Aurivillius type oxfluorides were studied by degradating Rhodamine B,methyl orange,methylene blue and methyl blue.Both Aurivillius type oxfluorides showed good photocatalytic performance.（2）Based on pure Aurivillius type oxfluorides,Bi₂TiO₄F₂ and Bi₂NbO₅F,low-temperature solvothermal method to obtain Aurivillius type composites was carried out by doping extraneous sources.The composites include Ag-Bi₂TiO₄F₂,g-C3N4-Bi₂TiO₄F₂,rGO-Bi₂TiO₄F₂,Ag-Bi₂NbO₅F,g-C3N4-Bi₂NbO₅F and rGO-Bi₂NbO₅F.The photocatalytic performance of the composites were measured by degradating Rhodamine B with different-content dopant under UV light.The experimental results show that the photocatalytic performances of composites become better and better with increasing dopant for Ag-Bi₂TiO₄F₂,g-C3N4-Bi₂Ti O₄F₂,Ag-Bi₂NbO₅F and g-C3N4-Bi₂NbO₅F.However,there exists a highest photocatalytic efficiency for rGO-Bi₂TiO₄F₂and rGO-Bi₂NbO₅F when their content rate of dopant in samples is three percent.