سنتز نانو ساختار هاي كربني دوپ شده با گوگرد و بررسي عملكرد آن ها به عنوان حسگر و جاذب از طريق محاسبات نظري

چكيده انگليسي :

Synthesis of sulfur doped carbon nanostructures and theoretical study of their applications as sensor and adsorbent Fahimeh Hassani Hasani90065@yahoo com F Hasani@ch iut ac ir January 2016 Department of Chemistry IsfahanUniversity of Technology Isfahan 84156 83111 I R Iran Degree PhD Language FarsiSupervisor Dr Hossein Tavakol Email hosein ta@yahoo com h tavakol@cc iut ac irAbstract In the theoretical part of this thesis first the geometries stabilities and electronic properties of simple andiodine adsorbed S doped fullerenes SFs with parallel and perpendicular configurations were studied usingdensity functional theory DFT calculations The adsorption energies in the gas and three solvents and thestructural geometries were discussed in all complexes To confirm the results AIM calculations NBOanalyses and population analyses were obtained The calculated energy gaps indicated that our complexeshad high conductivity comparing with SFs In other words the change in the energy gap showed that SFswere dramatically sensitive to the I2 molecules and could be used in sensor devices Then we have reported the sulfur doped carbon nanotubes SCNTs as a good adsorbent for iodine Thisability can be employed in sensor drug delivery and chemical reactions Adsorption energies in gas formand three solvents of iodine on the surface of SCNTs in various configurations were calculated using DFTcalculations and the interaction energies showed that these interactions for stable configurations areexothermic especially in the solvents Moreover QTAIM analyses confirm the potency of this interaction and 2 values defined that the nature of this interaction is non covalent NBO calculations showed the properinteraction between SCNTs and iodine Population analyses showed the increasing in the reactivity of SCNT Is versus SCNTs Moreover the electrical conductivity of the SCNTs was increased upon the iodineadsorption and they could be used in sensor devices for iodine detection In comparison to S doped fullerene adsorption values for SCNTs are more negative and SCNTs adsorb iodine more efficiently To realize theinteractions between CO molecules and different doped carbon nanostructures we study the adsorption ofCO molecule both direct and perpendicular configurations were considered on the surface of undoped andN B S doped CNT fullerene and graphene The calculated adsorption energies showed the adsorption ofCO on the surface of N doped carbon nanostructures is more favorable than the other structures and theprocess is exothermic due to the stronger bond energy of the C N bond versus C S and C B bonds In theexperimental section we have reportedthe growth doping of sulfur atom into the structures ofgraphene carbon submicron balls and CNTs with high sulfur content about 5 using chemical vapordeposition CVD technique The Fe CaCO3was employed as catalyst flow rate controlled acetylene gas wasintroduced in CVD furnace as carbon resource and the solid sulfur powder was place in the first zone of CVDas sulfur resource The structure size and specifications of prepared samples were determinedand confirmedby field emission scanning electron microscopy transmission electron microscopy X ray energy dispersivespectroscopy elemental mapping powder X ray diffraction Raman spectroscopy and X ray photoelectronspectroscopyanalyses The surface area and porosity of samples was obtained via Brunauer Emmett Tellerexperiment This method could be employed as an efficient fast and cheap technique for preparation ofsulfur doped carbon nanostructures Keyword Carbon nanotube Graphene Density functional theory Sensor Sulfur doping

حسني، فهيمه

سنتز نانو ساختار هاي كربني دوپ شده با گوگرد و بررسي عملكرد آن ها به عنوان حسگر و جاذب از طريق محاسبات نظري

نانو لوله كربني , گرافن , نظريه تابعي چگالي