The Preparation And Representation Of TiO₂ Nanorods Covered With MoS₂ Sheets

TiO₂ has attracted more and more attention and study du e to its low-cost,stabilization,environment-friendly and excellent photocatalytic performance.However,it is still limited on the application of catalyze visible light because of its wide band-gap.Meanwhile,MoS₂ nanosheets have novel structure,narrow band-gap,and show good photocatalytic performance of visible light.In this paper,composites of TiO₂ nanorods covered with Mo S2 nanosheets were prepared.Different methods and preparation conditions were inverstigated to find out the most ideal morphology and the catalysts with best photocatalytic performance.Details are as follow:First,different morphology of TiO₂ were synthesized by hydrothermal,calcinations and electrospum respectively.After that,they were covered with MoS₂ to form MoS₂/TiO₂ nanocomposites via hydrothermal.The XRD result shows the composites are all with the characteristic peak of TiO₂ and Mo S2 which means the exsitent of TiO₂ and MoS₂.Both TEM and SEM show that the amount of MoS₂ which vertical rooting into TiO₂ obtained by electrospum is most,indicating the formation of entire covered morphology.Moreover,the XPS shows the change of chemical states of Ti,O,S,Mo before and after covered with MoS₂,which reveals the actual combine of MoS₂ and TiO₂.The test of photocatalysis of methyl orange shows the MoS₂/ electrospum TiO₂ composites have the best effect with catalytic efficiency of 72%.Second,the synthesis conditions of MoS₂/calcinated TiO₂ was optimized via changing the time,temperature and pH of reaction and the molar ratio of Ti and Mo respectively.The products were investigated by XRD,TEM and the test of photocatalysis.The results show MoS₂ nanosheets grow gradually with the increase of temperature or time,and the composites have the best morphology while the temperature is 220 ? and the reaction time is 24 hours.Moreover,the morphology of Mo S2/TiO₂ composites is stable in neutral condition,while acidic or alkaline condition is against to form MoS₂ nanosheets and will break TiO₂ nanorods.Besides,when the molar radio of Ti/Mo is 2,MoS₂/TiO₂ composites show best photocatalyst properties.