Synthesis And Photo-catalysis/SERS Activities Of Titanium Dioxide Nanowires

TiO₂ is a typical wide-bandgap semi-conductive material,which has been investigated in the field of photocatalytic,solar cells and surface-enhanced Raman scatting?SERS?.One dimensional of TiO₂ nanowires exhibits more virtues compared with TiO₂ nanoparticles.Nanowires are more likely to absorb probe molecules and more stable when synthesizing composites owing to its network structure.In this paper,two kinds of composites were fabricated based on the above advantages.One is applied to photocatalytic experiments and the other is ultrasensitive to probe molecules in SERS test.The former is TiO₂-RGO aerogel,which can degrade organic pollutants under light.The addition of graphene accelerate the separation of photo-excited electrons and holes.This 3D structure is easy to recycle without the procedure of filtration,which is an improvement in utility.Compared with traditional TiO₂ nanoparticles,this material shows better photocatalytic properties through the experiment of MB degradation.The latter is Ag-TiO₂ nanowire network with surface defects by modified hydrothermal method.The as-prepared nanowires were dispersed on Si substrate followed by magnetic sputtering.Ag nanoparticles were uniformly deposited on TiO₂ nanowires.It is inspiring that the Ag-TiO₂ nanowire is capable of detecting R6 G Raman signal even in a highly diluted solution?10-19 M?,which is the lowest concentration for any detection limit reported in the literature.In addition,this substrate was also immersed into a mixed probe molecules solution,results revealed that different Raman signal can be obtained simultaneously.By the UV light cleaning,this substrate can be recycled.The thesis includes five chapters.The first chapter mainly introduces the definition of nanomaterial and the synthesis of one dimension TiO₂ nanowires.The second chapter analyses the edge of graphene aerogel and detailed synthesis procedure.Photocatalytic mechanism and the degradation experiment were described in the third chapter.Last but not the least is SERS application.Multiple tests were implemented to investigate the inner cause of such high sensitivity,such as XRD,SEM,TEM,XPS,PL,Raman and UV-VIS.The final part is conclusion.