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    Preparation and Investigation of the Electrochemical Behavior of Sensors Based on Glassy Carbon Electrode Modified with Various Carbon Nanostructures Decorated by Some of Metal Nanoparticlesfor Determination of Ceftizoxime

    , M.Sc. Thesis Sharif University of Technology Ranjbar, Saba (Author) ; Shahrokhian, Saeed (Supervisor) ; Masoumeh Ghalkhani (Co-Advisor)
    In the recent years, sensors and biosensors attracts much attentions as a suitable devices in analytical chemistry. In this meantime carbon nanostructures and metal nanoparticles act as a good choice owing to their unique properties such as high electrical conductivity andmechanical and chemical stability in modification of the surface of sensors and biosensors. Because of importance of analysis the trace amounts of pharmaceutical and biological compounds, in this studies the surface of glassy carbon electrode was modified with some carbon nanostructures and metal nanoparticles for electrochemical investigation and determination of pharmaceutical and clinical compounds.In the first work, a... 

    Fabrication of 3D Graphene/Gold Porous Electrode for Biosensing Applications

    , M.Sc. Thesis Sharif University of Technology Rahmati, Reza (Author) ; Simchi, AbdolReza (Supervisor) ; Tamjid Shabestari, Elnaz (Supervisor)
    Today, the use of carbon nanostructures hybridized with noble metals has attracted considerable attention for the fabrication of bio-electrochemical sensors. Since the specific surface area has an immense effect on the sensing response, three-dimensional structures of graphene have a great capability to utilize in these sensors. In this research, three-dimensional graphene was provided on the porous nickel foam by chemical vapor deposition technique. By evaluation of raman spectroscopy, the time period of 20 minutes for solving of the carbon atoms into the nickel foam was selected as the main parameter of optimized conditions for the synthesis of graphene. Afterward, production of few-layer... 

    Fabrication of dual-phase TiO2/WO3with post-illumination photocatalytic memory

    , Article New Journal of Chemistry ; Volume 44, Issue 46 , 2020 , Pages 20375-20386 Mokhtarifar, M ; Nguyen, D. T ; Diamanti, M. V ; Kaveh, R ; Asa, M ; Sakar, M ; Pedeferri, M ; Do, T. O ; Sharif University of Technology
    Royal Society of Chemistry  2020
    This study describes the synthesis of TiO2/WO3 composite systems with a varying concentration of WO3 by a glucose-template assisted method and demonstrates their round-the-clock photoactivity performance towards the degradation of methanol (MeOH) under illumination and dark conditions. XRD results indicated a biphasic anatase-rutile nature of TiO2, with tunable concentrations with respect to the WO3 loading. WO3 incorporation extended the light absorption of the system towards visible light, increasing the observed photoactivity. The obtained results were further validated using photo-electrochemical investigations such as photocurrent measurements and the impedance response of the systems.... 

    Electrochemical determination of CdS band edges and semiconducting parameters

    , Article Bulletin of the Chemical Society of Japan ; Volume 88, Issue 6 , February , 2015 , Pages 814-820 ; 00092673 (ISSN) Miandari, S ; Jafarian, M ; Mahjani, M. G ; Gobal, F ; Heidaripour, A ; Sharif University of Technology
    Chemical Society of Japan  2015
    Cadmium sulfide (CdS) thin film was electrodeposited on indium tin oxide (ITO) by chronoamperometry. The SEM images showed that hexagonal sheets of CdS deposited on the ITO surface. The X-ray diffraction (XRD) analysis confirmed this structure for CdS crystals and the average of crystalline size and the lattice constant parameters are approximately 39.54 and a = 0.4136, c = 0.6696 nm respectively. Photo-electrochemical investigations were performed by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) techniques. CdS band edges and density of states (DOS) were determined by CV technique. The band gap energy (Ebg) was measured... 

    Development of an electrochemical sensor based on (rGO-CNT) nanocomposite for raloxifene analysis

    , Article Materials Chemistry and Physics ; Volume 263 , 2021 ; 02540584 (ISSN) Ghalkhani, M ; Shahrokhian, S ; Navabi, M ; Sharif University of Technology
    Elsevier Ltd  2021
    A novel modified electrode is reported for the electrochemical investigation of the oxidation mechanism and also voltammetric determination of raloxifene (RLX). The surface of the electrode was modified with a thin layer of reduced graphene oxide-carbon nanotube nano-composite (rGO-CNT) was prepared, and successfully employed for the electrochemical studies of RLX. The morphology of the sensor surface was characterized by using a scanning electron microscopy. RLX Oxidation response significantly increased at the GCE covered with rGO-CNT, regarding the bare and CNT or rGO functionalized GCE. Experimental parameters affecting the RLX response were optimized and mechanism of the RLX oxidation... 

    Fabrication of nanoporous nickel oxide by de-zincification of Zn-Ni/(TiO2-nanotubes) for use in electrochemical supercapacitors

    , Article Electrochimica Acta ; Volume 100 , 2013 , Pages 133-139 ; 00134686 (ISSN) Gobal, F ; Faraji, M ; Sharif University of Technology
    NiO-ZnO/TiO2NTs electrodes were synthesized by the electrodeposition of Zn-Ni onto TiO2 nanotubes, dealloying in a concentrated alkaline solution and finally calcination of the resulting Zn(OH)2-Ni(OH)2/TiO2NTs at 300 C. Morphology of the electrodeposited nanostructures was studied using scanning electron microscopy (SEM) while their electrochemical characterizations were carried out using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge procedures. The SEM analysis revealed the nanoporous/cracked structures of the NiO-ZnO/TiO2NTs obtained at the electroplating time of 20 min. The EIS studies showed that nanoporous/cracked structures of... 

    Hydroxyapatite based and anodic titania nanotube biocomposite coatings: fabrication, characterization and electrochemical behavior

    , Article Surface and Coatings Technology ; Volume 287 , 2016 , Pages 67-75 ; 02578972 (ISSN) Ahmadi, S ; Mohammadi, I ; Sadrnezhaad, S. K ; Sharif University of Technology
    Elsevier  2016
    The main challenges of biological implants are suitable strength, adhesion, biocompatibility and corrosion resistance. This paper discusses fabrication, characterization and electrochemical investigation of anodized Ti6Al4V without and with a hydroxyapatite (HA) layer, HA/TiO2 nanoparticles (NPs) and HA/TiO2 nanotubes (HA/anodized). X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS) were used to characterize and compare properties of different samples. Dense HA with uniform distribution and 12.8 ± 2 MPa adhesive strength enhanced to 19.2 ± 4 MPa by the addition of TiO2 nanoparticles and enhanced to 23.1 ± 4 MPa by the... 

    Development of a nanocellulose composite based voltammetric sensor for vitamin B9 analysis

    , Article Current Nanoscience ; Volume 12, Issue 4 , 2016 , Pages 493-499 ; 15734137 (ISSN) Ghalkhani, M ; Shahrokhian, S ; Sharif University of Technology
    Bentham Science Publishers B.V 
    As a B group vitamins, vitamin B9 is a Water-soluble vitamin which is produced by plants and microorganisms (bacteria and yeasts). Vitamin B9 plays an important role in the production of proteins and nucleic acids in body and also is one of the substances that prevents the development of neural tube defects in the fetus. Methods: Electrochemical behavior of vitamin B9 was studied using a potentiostat/galvanostat SAMA 500, electroanalyzer system, I. R. Iran. A three-electrode system was used, including a glassy carbon working electrode (d = 2.0 mm, purchased from Azar Electrode Co., Urmia, I.R. Iran), an Ag/AgCl (saturated KCl) reference electrode and a Pt wire auxiliary electrode.... 

    Electrochemical investigation of electrodeposited platinum nanoparticles on multi walled carbon nanotubes for methanol electro-oxidation

    , Article Journal of Chemical Sciences ; Volume 129, Issue 9 , 2017 , Pages 1399-1410 ; 09743626 (ISSN) Mokarami Ghartavol, H ; Moakhar, R. S ; Dolati, A ; Sharif University of Technology
    Abstract: The electrodeposition of platinum nanoparticles (PtNPs) on multiwall carbon nanotubes (MWCNTs)/fluorine-doped tin oxide glass (FTO) was investigated. Nucleation and growth mechanisms were studied via Scharifker and Hills model. Chronoamperometry results clearly show that the electrodeposition processes are diffusion-controlled and the diffusion coefficient is 1.5×10-5cm2/s. The semi-spherical particles with lamellar morphology were observed in 1M H 2SO 4, while a petal shape was discerned in 0.5M H 2SO 4. Also, dispersion, size, and uniformity of PtNPs were investigated, where the finer distribution of PtNPs with the average size less than 100 nm was obtained in 0.5M H 2SO 4... 

    Mechanistic insights into photogenerated electrons store-and-discharge in hydrogenated glucose template synthesized Pt: TiO2/WO3 photocatalyst for the round-the-clock decomposition of methanol

    , Article Materials Research Bulletin ; Volume 137 , 2021 ; 00255408 (ISSN) Mokhtarifar, M ; Nguyen, D. T ; Sakar, M ; Pedeferri, M ; Asa, M ; Kaveh, R ; Diamanti, M. V ; Do, T. O ; Sharif University of Technology
    Elsevier Ltd  2021
    This study demonstrates the glucose-template assisted synthesis of hydrogen-treated Pt: TiO2/WO3 composites, and their round-the-clock photoactivity towards methanol (MeOH) degradation under light illumination and in dark. XRD indicated increasing rutile fraction in TiO2 as a function of template removal, WO3 crystallinity and H2 treatment process. The presence of oxygen vacancies in WO3 was confirmed by XPS. Lower recombination rate and higher surface area were observed in the optimized H2-Pt-G:TiO2/WO3 catalyst. The presence of oxygen vacancies and optical enhancements due to the synergistic interactions of the multi-system (TiO2, WO3 and Pt) extended the visible light absorption of the... 

    Electrochemical investigation of electrodeposited Fe-Pd alloy thin films

    , Article Electrochimica Acta ; Volume 56, Issue 1 , 2010 , Pages 483-490 ; 00134686 (ISSN) Rezaei, M ; Ghorbani, M ; Dolati, A ; Sharif University of Technology
    In the present study, the electrodeposition of Fe, Pd and Fe-Pd alloys, in alkaline solutions, has been investigated. Using ammonium hydroxide and trisodium citrate as the complexing agents, it has been shown that the co-deposition of Fe and Pd is achieved due to diminishing the difference between the reduction potentials of these two metals. Cyclic voltammetry results clearly show that the electrodeposition processes are diffusion-controlled and the diffusion coefficients of Fe2+ and Pd2+ are 1.11 × 10-6 and 2.19 × 10-5 cm2 s -1, respectively. The step potential experiments reveal that nucleation mechanism is instantaneous with a typical three-dimensional (3D) growth. At low overpotentials,... 

    Persian Liquorice extract as a highly efficient sustainable corrosion inhibitor for mild steel in sodium chloride solution

    , Article Journal of Cleaner Production ; Volume 210 , 2019 , Pages 660-672 ; 09596526 (ISSN) Alibakhshi, E ; Ramezanzadeh, M ; Haddadi, S. A ; Bahlakeh, G ; Ramezanzadeh, B ; Mahdavian, M ; Sharif University of Technology
    Elsevier Ltd  2019
    The Persian Liquorice was introduced as a sustainable corrosion inhibitor with excellent inhibition action for mild steel in sodium chloride solution. Persian Liquorice is a root of Glycyrrhiza glabra including many active compounds like Glycyrrhizin (GL), 18β- Glycyrrhetinic acid (GA), Liquritigenin (LTG), Licochalcone A (LCA), Licochalcone E (LCE), and Glabridin (GLD). The Fourier transform infrared (FT-IR) spectroscopy was utilized to track various active components exist in the Persian Liquorice extract. Electrochemical impedance spectroscopy, potentiodynamic polarization and electrochemical current noise measurements were conducted to investigate the corrosion inhibition role of various... 

    Simultaneous voltammetric determination of tramadol and acetaminophen using carbon nanoparticles modified glassy carbon electrode

    , Article Electrochimica Acta ; Volume 55, Issue 8 , 2010 , Pages 2752-2759 ; 00134686 (ISSN) Ghorbani Bidkorbeh, F ; Shahrokhian, S ; Mohammadi, A ; Dinarvand, R ; Sharif University of Technology
    A sensitive and selective electrochemical sensor was fabricated via the drop-casting of carbon nanoparticles (CNPs) suspension onto a glassy carbon electrode (GCE). The application of this sensor was investigated in simultaneous determination of acetaminophen (ACE) and tramadol (TRA) drugs in pharmaceutical dosage form and ACE determination in human plasma. In order to study the electrochemical behaviors of the drugs, cyclic and differential pulse voltammetric studies of ACE and TRA were carried out at the surfaces of the modified GCE (MGCE) and the bare GCE. The dependence of peak currents and potentials on pH, concentration and the potential scan rate were investigated for these compounds...