Bi-,25-FeO-,40-粉末的水熱合成及光學性能研究.pdf

1、武漢理工大學碩士學位論文BiFeO粉末的水熱合成及光學性能研究姓名：張成勇申請學位級別：碩士專業(yè)：材料物理與化學指導教師：孫華君20100401AbstractMaterialsofthesillenitefamily(B12M020，M=Si，Ge，Ti)exhibitphoticsandthermallyilnducedeffectsassociatedwithchangesinopticalabsorption，photorefr

2、activeandphotoconductivitybecauseofmeirspecialcrystalstructuresTherearefewreportsabouthydrothermalsynthesisandphoticspropertiesofBi25Fe040powdersuntilnowInthispaperBi25Fe040powdershadbeensuccessfullysynthesizedbyhydrothe

3、rmalmethodThephoto—absorption，photoluminescenceandphoto—catalyticpropertiesofBi25Fe040powderswerealsoinvestigated1)ThepurephaseofBi25Fe040powderswaspreparedbyadjustingtheconditionsofhydrothermalsynthesissuchasconcentrati

4、onsofmineralizer，timeandstoichiometryofreagentsNaOH，KOHandLiOHwerechosenasmineralizersWithLiOHasmineralizer，thesmallerparticleswereobtainedThehydrothermallygrowingmechanismandthestructureofBi25Fe040powderswerealsostudied

5、ItWasfoundthatconcentrationofmineralizerandstoichiometrywererelatedtothephaseandmorphologyofas—preparedsamplesWhenstoichiometryofreagentsischanged，thepureBi2sFe040powderswereobtained，whichreferedthatthestructureofBi25Fe0

6、40isstablewithgreatopenness21ThebandstructureofBi25Fe040WascalculatedwithAccelrysMaterialSufido40CASTEPmoldeandtheband—gapis2OeVThevalencebandismainlyconsistedofBi6sorbits02porbitsandpartofBi6porbits，whiletheconductbandi

7、sconsistedofpartofBi6porbits3)ItWasfoundedthatBi25Fe040powdershavegoodUVandvisiblelightresponseinthewavelengthof200nm～600nmwithanalysisofUV—Visdiffusespectrum，whichisconsistentwiththeresultofcalculationThephotoluminescen

8、cepropertyWastestedatroomtemperatureExcitedwavelengthis350nmandBi25Fe040powdersemitabluebandwiththecenterof469nmTheemissionpeaksarerelatedwiththebandstructureofBi25Fe0404)PhotocatalyticactivityofBi25Fe040powderswasevalua