7037

6579

كارشناسي ارشد

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

1390

چهارده، 63ص.: مصور، جدول، مودار

ص.ع. به فارسي و انگليسي

بهزاد رضايي، تقي خياميان

علي اصغر انصافي

11/7/91

محمد تقي جعفري، محمد سراجي

1396/09/18

كتابنامه

شيمي

شيمي

ID6579

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Electrospray Deposited Silver Nanoparticles on Pencil Graphite Electrode for Voltammetric Determination of Chromium VI Mahboobeh Dorvash m dorvash@ch iut ac ir Data of submission 14 February 2012 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiProf Behzad Rezaei B Rezaei@cc iut ac ir Taghi Khayamian Taghi@cc iut ac ir AbstractIn the current thesis the surface of carbon graphite electrode was modified by electrospray deposition of silvernanoparticles First of all silver nanoparticle colloids with a diameter of about 12 nm were synthesized bychemical reduction method Analysis of the UV Vis spectrum confirms this successful synthesis In thisresearch parameters of best electrospray deposition and thus the distance among the needle and the substratewas chosen as 14 mm and then the percentage of added methanol as 80 The scanning electron microscopy SEM micrographs confirm the deposition of silver nanoparticles and the formation of a thin layer on theelectrode surface Also studied electrochemical behavior of this modified electrode in a nitric acid solution arestudied for the determination of chromium using cyclic voltammetry CV linear sweep voltammetry LSV differential pulse voltammetry DPV and electrochemical impedance spectroscopy EIS The results show thatthe presence of silver nanoparticles on the electrode increases the catalytic current of chtomium VI Analysis ofthe amount of the active surface electrode shows the 1 30 fold increase in this surface versus in the unmodifiedelectrode Electrochemical parameters were optimized for the measurement of chromium VI First aconcentration of 0 01M nitric acid was chosen To increase the sensitivity of the method a Differential PulseVoltammetry technique in the potential range of 0 90V to 0 10V with modulation amplitude of 70 mV andscan rate of 20 mV s was used A Preconcentration time of 60 seconds at a 0 00 V potential versus the Ag AgClreference electrode was chosen The study was performed in the concentration range of 0 01 to 80 mg L ofchromium VI Detection limit was 0 063 mg L The relative standard deviation RSD for 30 mg L Cr VI was 4 6 Impedance studies show that the charge transfer resistance in the modified electrode decreased whichconfirms the catalytic effect of silver nanoparticles deposition on the surface Interference of some cations inwater samples was investigated At the end this method was used for the measurement of chromium VI in realsamples of wastewater Comparing the results with those of the standard method for measurement ofchromium VI by the means of t and F tests reveals the success of this electrode in the measurement ofchromium VI in the real samples Keywords Pencil graphite electrode Electrospray deposition Chromium VI Silver nanoparticles

بهزاد رضايي، تقي خياميان

علي اصغر انصافي

محمد تقي جعفري، محمد سراجي