13558

1194 دكتري

دكتري

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

۱۳۹۶

بيست و يك، [۱۲۴]ص.: مصور، جدول، نمودار

بهزاد رضايي

علي‌اصغر انصافي

حسن حداد زاده، محمدتقي جعفري، محمد محسن مومني، مسعود آيت اللهي مهرجردي

1397/03/07

كتابنامه

شيمي

شيمي

ID1194 دكتري

114 New synthesis of 2D and 3D reduced graphene oxide nanocomposites with low cost transition metal characterization and application in fuel cells and supercapacitors Ahmad Reza Taghipour Jahromi Email ar taghipourjahromi@ch iut ac ir March 2018 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranSupervisor Prof B Rezaei Email Rezaei@cc iut ac irAdvisor Prof Ali A Ensafi Email Ensafi@cc iut ac irDepartment Graduate Program Coordinator Assoc Prof Ali R Najafi Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Tel 98 31 33913268 Fax 98 31 33912350Abstract In this thesis at the first a one step wet chemical method was used to synthesis of reduced grapheneoxide nanoflakes 2D RGONF from graphite by a thermal reduction at low temperature This method issimple and avoids the usage of harmful chemical reductants Then a new electrocatalyst consist of Ni Co Senanoparticles were deposited on RGONF Ni Co Se@RGONF by solvothermaly method The average sizeof nanoparticles which deposited on RGONF was about 80 nm Then a glassy carbon electrode GCE wasmodified with Ni Co Se@RGONF and was used as an electrocatalyst for hydrogen evolution reaction HER in 0 50 mol L 1 sulfuric acid The results show that the RGONF Ni Co Se has an excellent catalytic activitytoward HER with overpotential Tafel slope and stability about 5 mV vs RHE 30 3 mV decade 1 and atleast 20days in sulfuric acid respectively These results are comparable with C Pt 20 as a commercialelectrocatalyst for HER At the second study a new hybrid material consisting Co OH 2 magnetic nanoflake MNF Co OH 2 grown on reduced graphene oxide nanoflake MNF Co OH 2@RGONF was synthesized by a facile andinexpensive technique Then the MNF Co OH 2@RGONF GCE was used as a bi functional electrocatalystfor the OER and ORR in alkaline media The onset potential current density at 2 025 V vs RHE and Tafelslope of OER in 1 0 mol L 1 KOH for MNF Co OH 2@RGONF modified glassy carbon electrode MNF Co OH 2@RGONF GCE were about 1 505 mV vs RHE 227 mA cm 2 and 63 mV dec 1 respectively Sothat the current density and Tafel slope of this electrocatalyst are better than commercial IrO2 Furthermore itwas concluded that MNF Co OH 2@RGONF GCE due to four electron transfer mechanism better durabilityand stronger resistance rather than Pt C 20 at 0 436 V in KOH 0 10 mol L 1 with the addition ofmethanol to electrochemical cell has a high catalytic activity for ORR At the 3th study a new synthesis of Co OH 2@RGONF nanohybrid via a facile hydrothermal procedurefor feasible operation as a supercapacitor compound and OER electrocatalyst in alkaline media TheCo OH 2@RGONF GCE as a supercapacitor electrode with potential windows of 0 35 V exhibits a powerfulspecific capacitance 235 20 F g 1 at 0 1 A g 1 current density energy density stability about 90 of theinitial capacitance value maintain after 2000 cycles at 1 0 A g 1 and fast charge discharge ability

بهزاد رضايي

علي‌اصغر انصافي

حسن حداد زاده، محمدتقي جعفري، محمد محسن مومني، مسعود آيت اللهي مهرجردي